Question: I use git bash under windowsXP system.I try to enter my USB Disk by entering "cd G:" in git bash,but it apears that "sh.exe : cd : g:: No such file or directory".

I can open my USB Disk under my system.

What's wrong with it ?How can i solve the problem?

Answer: 
Git bash uses the `/x` form to identify the root of drives, instead of `X:`. Doing `cd /g` should work correctly (you'll likely see similar paths while working within it). 

I believe this is just how bash handles the drives on Windows (it is used through all the versions of git bash I've used, on XP through 7).
you can go down to the root of your computer by using the "cd .." command until you can go any further the copy the path from your flash drive and past it in the bash command. eg "cd D:\website" where D is the external flash drive.