avast cleaner can't find virus

According to a virus scan I performed, there is a virus in my system.
The file cannot be deleted or put into the chest.
I ran avast cleaner, but according to the report, a series of files and folders could not be scanned.
As a result no virus what found.
What to do?
Thanks

Hi flyingcarpet,

What was the name and location of the file detected as a virus? What was the name of the virus? What program detected it? Do you have avast! installed? avast! cleaner only has a limited number of detections, and the installed avast! scanner has many more, but you mustn’t install it alongside another anti-virus program. If you do install avast! as you AV program, first try a boot time scan with avast! Right click the scanner screen, select ‘schedule a boot time scan’ and reboot when requested.

Many innocent files and folders cannot be scanned, so don’t worry too much about those reports.

What was the reason it couldn’t be moved the the chest, etc. errors, file in use is common (boot-time scan as FWF mentioned should get round that).
Deletion isn’t really a good first option (you have none left), ‘first do no harm’ don’t delete, send virus to the chest and investigate.

See http://forum.avast.com/index.php?topic=35347.msg297170#msg297170 this topic for more information on why files can’t be scanned.