git.exe is required by TortoiseGit; see this nice StackOverflow answer for clarificationCheck the system prerequisites which are listed above.
As a command-line git client is required for using TortoiseGit, you have to install both. The recommended order is to install TortoiseGit first.
Just download the setup package for your system and install it. If you want a localized interface of TortoiseGit, also download a language pack and install it. If you are running a 64 bit system, you do not need to download and install the 32 bit version: the 32 bit shell extension is included in the 64 bit installer since TortoiseGit 1.7.3.0.
Before upgrading you should read the release notes so that you know what changed.
Just download the setup package for your system and install it. The old version will be replaced automatically. If possible please use the automatic updater of TortoiseGit (in this case the binaries are cryptographically verified). You can trigger an update check by going to the about dialog of TortoiseGit and clicking "Check for update".
If you are upgrading from 1.7.3.0 or older and you have installed the 32-bit version on a 64-bit system you have to uninstall the 32-bit version first.
There are some error messages which are more common:
C:\Users\<your user>\AppData\Local\Temp, C:\User and Settings\<your user>\Local Settings\Temp, c:\Windows\Temp\).TortoiseGit is a shell extension. Any program that displays an Explorer-like dialog (such as a File Open or Save dialog) will load TortoiseGit.dll. Therefore, many processes might require to be restarted, but due to known installer issues that are outside the scope of TortoiseGit, this can go wrong. The easiest workaround is to first close all applications before running an install/upgrade. For more info, see also issue #2557.
Basically just install a new version of Git for Windows. Then, it is recommended to open TortoiseGit settings and selecting "Check now". This should do the trick and update/restart all components of TortoiseGit. If you just installed a Git for Windows version >= 2.24 and you use the Shell status cache, it is recommended to log-off and on again for changes in the Windows Explorer to take effect.
(Based on a similar TortoiseSVN FAQ entry.)
You may find that not all of these icons are used on your system. This is because the number of overlays allowed by Windows is limited to 15. Windows uses 4 of those, and the remaining 11 can be used by other applications. And if you have OneDrive installed, that uses another 5 slots. If you then have another cloud drive tool installed, those slots can be used up. TortoiseGit and TortoiseSVN try to be a "Good Citizen ™" and limit its use of overlays to give other apps a chance.
You can check which other apps are using overlays by using Regedit to look at HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\ShellIconOverlayIdentifiers (and also HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\Explorer\ShellIconOverlayIdentifiers on 64-bit Windows for 32-bit applications).
Other apps which are known to use overlays:
If there are too many overlay handlers installed and TortoiseGit does not show any overlays, you can try to delete some of the installed handlers from the registry. But be careful when editing the registry!
The overlay handler are loaded by the order of the ASCII code. Thus, you need to make sure the Tortoise* overlay handler has a high precedence to be honored. Deletion of other handlers is sometimes a bit tricky. But you can also try to prefix the Tortoise* entries with spaces and/or double quotes (") - in general there seems to be a real war going on who has the most spaces.
Please also see issue #692 and issue #2548 and this answer on StackOverflow for more user reports.
(Based on a similar TortoiseSVN FAQ entry.)
Go to the Settings -> Icon Overlays and check the drive types for which you want to see overlay icons. Be aware that enabling overlays for network drives will slow down not only TortoiseGit but the whole system.
Based on a similar TortoiseSVN FAQ entry
In case files have no overlay icon and folders are displayed as modified the setting "Show excluded folders as normal" is active. Go to Settings -> Icon Overlays and make sure the path is not on a disabled drive type and is not explicitly excluded as an "Excluded path".
There is a very good answer on StackOverflow.
There is a very good answer on StackOverflow.
There is a very good answer on StackOverflow.
There is a very good answer on StackOverflow.
There is a very good answer on StackOverflow.
When you use TortoiseGitPlink (the default), see this very good answer on StackOverflow. If you want to use OpenSSH, see this answer on StackOverflow. You might also be interested in this answer on StackOverflow.
Create an environment variable called "GIT_SSH" with the path to the PuTTY plink.exe or preferably to TortoiseGitPLink.exe. This can be done on the command line by executing "set GIT_SSH=PATH_TO_PLINK.EXE" ("C:\Program Files\TortoiseGit\bin\TortoiseGitPLink.exe" on default installations) or permanently.
There is a very good answer on StackOverflow.
TortoiseGit uses TortoiseGitPlink by default as SSH client. PuTTY and TortoiseGitPlink do not respect ~/.ssh/config (which is the config file for OpenSSH). Both tools store, like Windows tools, their configuration in registry.
Please see the TortoiseGit Manual - Tips and tricks for SSH/PuTTY for configuration hints.
If you want to use OpenSSH, set the SSH client to ssh.exe in TortoiseGit network settings (there is no need to use the full path to "ssh.exe" as it is on the %PATH%).
(Based on an answer on StackOverflow.)
You have to reset the menu bar (even if you did not make any changes to it). Left click -> Customize -> Menu tab and hit Reset/Restore.
The commit, the log and several other dialogs allow to adjust the size of some GUI elements. There is a slider between the GUI elements which allows to resize some GUI elements vertically, cf. issue #1761.
There are several reasons why non Git for Windows git.exe are not officially supported by TortoiseGit. MSYS2 Git, Cygwin Git and WSL Git run in an emulated *nix environment:
The TortoiseGit developers only use Git for Windows. Bug reports, however, are welcome.