Open with comes on clicking drives..:

1.go to run->msconfig->startup

2.u will see a list of startup program in that disable the amvo.exe

STEP 1&2 are very important bcz without doing that if u delete the virus it will automatically be created (bcz amvo.exe is a autorun program)
if the problam is not solved still then i think ur registry value is changed by the virus
for this go to run->regedit->local machine->software->microsoft->windows->current version->explorer->advanced->folder->hidden->showall->change the checked value from 0 to 1.see to that it remains 1 even if u close run and come again.
after that restart the system.

THIS CAN ALSO BE USED IF THE DRIVES ARE NOT OPENING....
(if a drive is not opening or asking open with at each time do all the above steps and when it asks for open with give explorer) and restart the system