It looks like GIT_TRACE (Edit: see PS) variable is enabled in your environment. The environment settings almost always[*] are stored so that they are not affected by git reinstallation.
It looks like the directory C:\Users\
is not usually writable for users, that's why you are getting the error.
To fix the issue, open your environment variables settings and look up there for the variable GIT_TRACE...
to remove it. If it's not there is can be in the shell start script like ~/.bashrc
. Check if the issue reproduces if you start the git from cmd.exe
.
[*] there may be some files in /etc
which may affect environment of the bash session and are usually removed at git for windows uninstallation. But it is very unlikely anybody has touched them.
PS: actually, there are many variables like "GIT_TRACE...", scroll down in the document for them.