This is only 1 item to check for a possible fix for no localhost and/or 127.0.0.1 access on the PC that XAMPP is installed on.
Open
C:\Windows\system32\drivers\etc\Hosts file in your text editor and look for:
127.0.0.1 localhostIf it is not included then add it as the first line after all the commented lines.
Also if you have this line:
::1 localhostComment it out so it looks like this:
# ::1 localhostNow the first 2 lines should look like this:
127.0.0.1 localhost
# ::1 localhostSave the file and try again to access
http://localhost or
http://127.0.0.1Also check that firewall access is allowing access and virus scanners are allowing access - temporarily disable these to test.
In Vista make sure you have disabled UAC and you are logged in as an administrator or a
super administrator.
And of course make sure that Apache and MySQL are both actually running.