ya then u are affected with a virus......if you haven't not already scanned ur PC then do it now....if there is no virus then do the following
Goto Run and type 'regedit'(without quotes)
now navigate to
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Exp lorer\Advanced\Folder\Hidden\NOHIDDEN
on the right window look for the DWORD 'CheckedValue' and
make its value 2, look for another DWORD 'DefaultValue' and make its value 2
again navigate to
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Exp lorer\Advanced\Folder\Hidden\SHOWALL
on the right window look for the DWORD 'CheckedValue' and
make its value 1, look for another DWORD 'DefaultValue' and make its value 2
Restart your PC and you may now be abale to see the hidden files....
regards
ayush_chh