Windows Pro

There is a PC that is infected with worm called w32.gammima.ag. Symantec AV cleans it when the PC starts everytime. SAV quarantines files avpo.exe and mgg.exe. They are deleted permanantly via the quarantine. Apparantly, the aforementioned files were malware that also created a autnorun.ink file in the C drive. Ability to view hidden files is crippled by the worm. I suspect that is because the autorun.inf file is a hidden file. Unfortunately, the infected account is an administrator account. The PC in question is also very slow now. The registry keys that should be on the infected PC are not present. Given all that, is there some way to get rid of the worm and restore the PC to normal working order?