1. What are µTorrent’s system requirements?

Very low. It works on as weak a system as Windows 95 on a 486 with 14MiB of RAM, up to 2003 and Vista. It also works on 64-bit Windows.
It’s reported to work under Linux using Cedega with some issues (blue bars in Pieces and Files tab don’t work, update function fails, minimize has a slight bug) if you use «Win98″ mode.
It works very well under Wine 0.9.16 (especially with µTorrent 1.6), but versions previous to 0.9.15 might have issues or not work at all. There are some minor bugs.
It will also work under FreeBSD 6.1 using Wine 0.9.16+, but requires the GLX module to be enabled in xorg.conf.
It will NOT work in Darwine 0.9.12 on OSX. It is reported to work, however, in CrossOver Office alpha 2 and 3, though you can’t minimize for more than a few seconds without it freezing.
All 9x systems should have at least IE 4.0 installed: it upgrades a system DLL that provides functionality for various µTorrent functions. However, it is not necessary for µTorrent to run. Without it, only the toolbar, graphs in the pieces view, and double clicks in the list view no longer function.
Be warned that Windows 95/98 are limited to 100 max concurrent connections, unless you apply the following registry tweak:
Open the registry editor (Start -> Run -> regedit), go to HKEY_LOCAL_MACHINESystemCurrentControlSetServicesVxDMSTCPYou must create the following entry, it is not present by default.

Data Type: String

Specifies the maximum number of concurrent connections. The default is 100. The maximum is 512.

2. Is µTorrent open source?

No. It is not likely to become open source ever.

3. Is there a Linux or Mac version?

The OSX port is in progress. A Linux port is currently not planned for the future.
However, it is possible to run µTorrent under Wine and Cedega.

4. How do I make µTorrent prioritize the first and last piece?

Go to the Advanced section and set «bt.prio_first_last_piece» to true.

5. How do I make µTorrent allocate all the files when I start the torrent?

Turn on «Pre-allocate all files» in Downloads. Turning on this option will prevent compact storage from working, however. Pre-allocate no longer allocates all files when skipping files, only the ones you choose.
There is little use to pre-allocate except for making sure you have enough space when starting a torrent. It does NOT reduce fragmentation as compared to not using it, since µTorrent ALWAYS allocates the full file when writing to prevent fragmentation, regardless of if pre-allocate is on (unless you use sparse files).

6. How do I modify the disk cache options?

(1.6 and later) While the defaults should work fine, even up to 100Mbit, you may want to alter the disk cache options. You will find the options in Advanced -> Disk Cache. To see the current cache use, look at the Speed tab, and choose Disk Statistics from the drop-down list.
The cache size is a combined size, you cannot specify an individual size for read and write caching.
Reduce memory usage when cache not needed will release all the memory for the write cache when you are not downloading.
Write out untouched blocks every 2 minutes will control whether µTorrent flushes the chunks from incomplete pieces to disk if the piece has been inactive for 2 minutes. Turn this off if using very large cache values or experiencing disk overload during your download (NOT if you just added the torrent, that is normal!).
Write out finished pieces immediately will control whether µTorrent writes finished pieces immediately. If turned off, it will write them after a maximum of 15 seconds. Turn this off if using very large cache values or experiencing disk overload during your download (NOT if you just added the torrent, that is normal!).
Turn off read caching when the upload speed is low will turn off read caching when the upload speed is <100 KB/s, where the read cache is more likely to do harm than good.
Remove old blocks from cache will remove unused blocks after a certain amount of time has passed since they were used. Turn this off if using very large cache values.
Increase automatic cache size when cache thrashing will make µTorrent increase the automatic cache size if you are experiencing disk overloads, because of very high speeds or a slow disk. Do NOT turn this on if you are experiencing disk overload while you just added the torrent, that is normal.

7. How do I change the default remove action?

(1.5.1 beta 460 and later) Right click the remove toolbar, and hold shift when choosing the option.

8. How do I make µTorrent delete files to the recycle bin?

(1.5.1 beta 460 and later) Right click the remove toolbar, and check «Move to trash if possible.»

9. Is it possible to make µTorrent load a torrent from the commandline?

Yes. The syntax is as follows: uTorrent.exe /directory «C:Save Path» «D:Some folderyour.torrent»
You must not have a trailing backslash in the save path, else µTorrent will fail to load it. This works for both single-file and multi-file torrents.

10. How can I add other columns of info? Can I sort by more than one at the same time?

Right click on the column (either on the main section of the window, Files, or Peers tab), and check the columns you want to add or remove.
You can sort by any column by clicking on it. Press shift click on a column to setup a secondary sorting order.

11. How can I quickly change the upload and download caps?

You can right click on U: or D: in the status bar to do this, or right click on the tray icon. Alternatively, you can set it in Network.
You can override the automatic values in the right click menus by adjusting the Speed Popup List in Advanced -> User Interface.

12. How can I tell if a peer is an incoming or outgoing connection?

In the Peers tab, check the Flags column. If the peer has an I in the column, it means it’s an incoming connection.
A blank port in the Ports column means incoming but peers with a non-empty port can also be incoming, the only reliable way to tell is with the I flag.

13. How can I make µTorrent stop seeding at a specific share ratio?

Go to Queueing in the options, set the ratio/time you want, check the box next to «Limit the upload rate to» and write 0. If you simply want to allocate less bandwidth, use a non-zero value. If you want seeding to take priority over downloading, turn on «Seeding tasks have higher priority than downloading tasks», which will make your downloads get queued. 0 means 0% for the ratio, -1 is infinite.
-1 is used so you can have all torrents seed forever by default, and let you manually set a seeding ratio on each individual torrent’s properties so that only those torrents stop. For this to work, you must still check «Limit the upload rate to» and write 0.

14. How can I make µTorrent auto-load torrents from a specified folder?

Simply turn on «Automatically load torrents in directory:» in Other, specify the folder, and hit OK. µTorrent will load the torrents soon after they’re added to that folder, though it will ask you where to save them. If you want it to automatically save to a folder, turn on «Put new downloads in» in Downloads and specify your download folder. However, turning on «Put new downloads in» will prevent the BitComet-style add torrent dialog from showing up, unless you use File -> Add Torrent (no default save) or turn on «Always show dialog on manual add.» You can turn on «Delete torrent instead of renaming, when loading» so it deletes the torrent after loading, instead of renaming it to .torrent.loaded.
Please note that the auto-load folder CANNOT be either %Appdata%uTorrent, OR the folder you specified for «Store .torrent files in.» If you use the same folders for both, you WILL have problems.

15. How can I rename a torrent’s folder?

If you’re adding a new torrent, you can rename it with the BitComet-style add torrent dialog by simply changing the save path (the folder doesn’t have to exist). If the torrent already exists, stop the torrent, rename the folder to whatever you like, then in µTorrent, right click on the torrent, pick Advanced -> «Set download folder», and point it to the newly renamed folder. Then, simply start the torrent again (no need to force re-check).

16. How can I rename a torrent in the main listview?

(1.5.1 beta 460 and later) Select the torrent and press F2, or single click. Pressing Esc will cancel the rename.

17. How can I make µTorrent append a !ut extension to incomplete files?

This option was added in the 1.3.1 betas. Simply turn on «Append !ut to incomplete files» in Downloads. This will instantly rename ALL incomplete files to have !ut at the end of the filename, regardless of if the torrents are started, stopped, paused, or queued. Turning it off will undo the operation.

18. How can I make µTorrent start minimized?

Simply add /MINIMIZED to the command line. Either modify the shortcut, or if you want it to start minimized when starting with Windows, open the registry editor (Start -> Run -> regedit), browse to HKEY_CURRENT_USERSoftwareMicrosoftWindowsCurrentVersionRun, double click on µTorrent’s entry, and append /MINIMIZED to the end of the command.

19. How can I make µTorrent start in bosskey mode?

(1.5.1 beta 460 and later) Add /HIDE to the shortcut/path. Make sure you’ve set a bosskey beforehand, otherwise you will have to end the process and start it again without /HIDE to access it.

20. How can I make µTorrent go into a seed-only mode on all torrents?

If you want it to automatically go into a seed-only mode at specific hours with the scheduler, you can hold shift (in 1.4.1 build 417 and later) while selecting the hours and the blocks should turn red, which indicates a seeding only mode.
If you want to manually make a download go into a seed-only mode, you can skip all the files in the torrent, and after a minute or so, it should start seeding. It’s not instant because it has to finish up the last few queued pieces.

21. Can µTorrent automatically move files when the torrent finishes?

Yes, you can set this in the Downloads section. It can move it to another folder, or to another partition.
If you have not set a directory for «Put new downloads in:», you must uncheck «Only move from the default download directory.»
If you check «Append the torrent’s label to the directory name», the label is used as the subdirectory name for finished torrents with that label.
You MUST set a directory for «Move completed downloads to:» for this option to work.
Since labels automatically disappear when unused, you can use set persistent labels that don’t disappear in Advanced -> User Interface.

22. What is %AppData%?

%AppData% is a system variable that works on every Windows OS.
To use it, you can either type %AppData%uTorrent into the Address Bar, or click Start -> Run, and type it there.

23. What do all these BitTorrent terms mean, such as seeder, snubbed, etc?

See BTFAQ.com’s Definitions of BitTorrent Terms

24. What do all those flags in the Flags column mean?

D = Currently downloading (interested and not choked)
d = Your client wants to download, but peer doesn’t want to send (interested and choked)
U = Currently uploading (interested and not choked)
u = Peer wants your client to upload, but your client doesn’t want to (interested and choked)
O = Optimistic unchoke
S = Peer is snubbed
I = Peer is an incoming connection
K = Peer is unchoking your client, but your client is not interested
? = Your client unchoked the peer but the peer is not interested
X = Peer was included in peerlists obtained through Peer Exchange (PEX)
H = Peer was obtained through DHT.
E = Peer is using Protocol Encryption (all traffic)
e = Peer is using Protocol Encryption (handshake)
L = Peer is local (discovered through network broadcast, or in reserved local IP ranges)

25. What do the red icons (Tracker Error (download)/Tracker Error (upload)) mean on the torrent status icons?

These red icons indicate that µTorrent was not able to reach the tracker. This could happen when the tracker goes offline, becomes overloaded, or when the domain simply doesn’t exist anymore. Check Tracker Status on the General tab to see what the exact error message is.
In many cases, seeing this (especially if you see hostname not found in Tracker Status) and having DHT on but still having no peers to connect to may mean that you’ll have to find another copy of the torrent on another tracker.
In some cases, this is normal because the tracker is overloaded or temporarily down. The torrent itself should keep seeding/downloading as long as you got some peers, and if the tracker comes back up or becomes responsive, you should have no lost ratio so long as you don’t close µTorrent or stop the torrent.

26. What do all the status icons mean?

means the torrent is downloading
means the torrent is downloading, but there is a tracker error
means the torrent is seeding
means the torrent is seeding, but there is a tracker error
means the torrent is a queued download
means the torrent is a queued seed
means the torrent is a stopped download
means the torrent is a stopped seed
means the torrent is paused
means the torrent has an error

Labels are a powerful feature in µTorrent. They can be used for simply labeling your torrents to identify them, or to use for sorting the torrents more easily. For example, you could label your torrents from private trackers as «private», and then click on the Labels column to easily sort all your private torrents. You can select one torrent or more than one to apply a label.
Simply right click on the torrent(s), go to Label, and click «New label…» to add a label, or select an already existing label. This can be done regardless of it a torrent already had a label.
To remove a label from a torrent, right click the torrent, Labels -> Remove Label.
Unused labels are automatically removed from the list.
If you would like labels that never disappear, you can add persistent labels in Advanced -> User Interface.
The benefit of normal and persistent labels is that they can be used in tandem with «Move completed downloads to» in the Folders section. The label would be used as a subdirectory to place the completed download in.

28. What do the colors in the Availability graph mean?

The color red means the piece is not available amongst the peers you’re connected to. (this means availability is less than 1 and you may not be able to complete the torrent)
Pale blue means that the piece is present amongst the peers you’re connected to, but rare.
The darker the blue, the more common the piece is in the swarm.

29. What do all those colors in the Pieces tab mean?

Dark blue means the data is downloaded and written to disk.
Medium blue means the data is downloaded but still in the cache.
Light blue means the data has been requested from one peer.
Green means the data has been requested from multiple peers.

30. What do the colors in the files tab mean?

Blue means the data has been written to disk. Green means the piece is being actively downloaded.

31. What does Wasted and hashfails mean?

Wasted shows a combination of discarded data and bad data. Discarded data is data that’s sent to you by a peer that your client didn’t want. Hashfails happen when bad data is received and the piece fails the integrity check.
Do not worry if this happens, since the data that fails the integrity check is discarded and re-downloaded. If you get an abnormal (hundreds of MB) amount of hash fails, it may be a poisoned torrent. If the torrent never finishes (gets stuck at 99.9% and has tons of hash fails), your router may be mangling the packets.

32. What does availability mean?

That number tells you how many unique copies of the file are available between yourself and the peers you’re connected to. If this is less than 1, you most likely will not be able to complete the torrent. The only thing you can do is wait and hope a seeder hops onto the torrent to allow you to complete it. You can also try and request a «reseed» on the tracker’s forum. Sometimes, this may never happen because the torrent was abandoned, and you may need to find the torrent elsewhere.

33. What does Force Start (Downloading [F] / Seeding [F] ) do?

Force Start is a way to start torrents to bypass queue settings and seeding priority settings. It can also be used to make torrents keep running/start in «Turn Off» hours with the scheduler. For example, if you set it to run 2 torrents max, but wanted to run a third, you could Force Start the third one. Forced torrents do not count towards the queue settings. Or, if you had torrents set to stop at 150% share ratio, but wanted one to keep going, you could Force Start it and it would not stop at 150%.
You can make a torrent Force Start by right clicking on it, and choosing Force Start. This works regardless of it the torrent is stopped, queued, or started. To set it back to normal mode, right click on it and choose Start.

34. What does Bandwidth Allocation do?

This is an option that makes µTorrent allocate less or more bandwidth towards a torrent. This only affects upload, and only if an upload cap is set.

35. How is the share ratio shown for torrents that are started fully complete?

It starts at 0.000 instead of ? to give you an estimate of how much of the file has been distributed. It is amount uploaded / file size.

36. What is the Logger tab and what does it do?

You can log to a file by right clicking -> Log to file. Be sure to specify the FULL SAVE PATH, including the filename. This will not save the buffer, only lines that showed up after you set it. To stop logging, go back to Log to file and hit OK with nothing written in the box.

37. What is that magnifying glass and box for?

That is µTorrent’s search bar. Click on the magnifying glass to select what site you want to search on, then type what you want to search for and press enter. This will launch your browser. You can add and remove sites to the list by going to Advanced -> User Interface and editing the Search Engines box.