Hi,
please give us some details to help you better:
WHAT said you had this virus ?
1) the mail itself
2) avast mailscanner
3) avast Standard-Shield ?
for 1) or 2): delete the email
for 3):
try booting to SafeMode (F8-Boot) and move the file to quarantine with avast (do a complete/thorough & archive scan)
How-to: -> see link "VirusRemoval" below
If that doesn't solve it:
Please work through the link "VirusRemoval" below in my signature, and come back with specific infos, e.g.
- windows & avast version
- location/folder/filename of infected file
- results of onlinescanners on the file
- a hijackthis-Log for diagnosis