I have noticed since upgrading SourceTree that I can no longer remove or move or rename local repositories after using sourcetree. This is because sourcetree is leaving behind an un killable set of processes which only a reboot will clear.

git.exe
conhost.exe
git.exe

e.g. Using process hacker 2

"C:\Users\Me\AppData\Local\Atlassian\SourceTree\git_local\cmd\git.exe" --no-pager -c color.branch=false -c color.diff=false -c color.status=false -c diff.mnemonicprefix=false -c core.quotepath=false diff --unified=3 -M --cached --no-color --no-ext-diff – src/images/leaderboard.png

Started: 2 hours and 12 minutes ago (16:05:37 19/08/2015)

PS C:\Users\Me> taskkill /im git.exe
ERROR: The process "git.exe" with PID 9604 could not be terminated.
Reason: This process can only be terminated forcefully (with /F option).
ERROR: The process "git.exe" with PID 8856 could not be terminated.
Reason: This process can only be terminated forcefully (with /F option).
ERROR: The process "git.exe" with PID 9608 could not be terminated.
Reason: This process can only be terminated forcefully (with /F option).
ERROR: The process "git.exe" with PID 5880 could not be terminated.
Reason: This process can only be terminated forcefully (with /F option).
ERROR: The process "git.exe" with PID 5892 could not be terminated.
Reason: This process can only be terminated forcefully (with /F option).
ERROR: The process "git.exe" with PID 240 could not be terminated.
Reason: This process can only be terminated forcefully (with /F option).

Using /F does not kill them either, giving

PS C:\Users\Me> taskkill /im git.exe /f
ERROR: The process "git.exe" with PID 9604 could not be terminated.
Reason: There is no running instance of the task.
ERROR: The process "git.exe" with PID 8856 could not be terminated.
Reason: There is no running instance of the task.
ERROR: The process "git.exe" with PID 9608 could not be terminated.
Reason: There is no running instance of the task.
ERROR: The process "git.exe" with PID 5880 could not be terminated.
Reason: There is no running instance of the task.
ERROR: The process "git.exe" with PID 5892 could not be terminated.
Reason: There is no running instance of the task.
ERROR: The process "git.exe" with PID 240 could not be terminated.
Reason: There is no running instance of the task.

Windows 8.1