I just upgraded to Git 1.8.0.1 for Windows, from my previous version 1.7.9.mysysgit.0. I downloaded the new version from the Git site and installed through the normal Git in
if you just type
$ git update
on bash git will inform you that 'update' command is no longer working and will display the correct command which is 'update-git-for-windows'
but still the update will continue you just have to press " y "
if you are having issues on it run the bashh as administrator or add the 'git.exe' path to the "allowed apps through controlled folder access".