the other day i got a virus and now i cart open avast home addition
i keep getting “avast!:the aavm subsystem detected a rpc error” and avast virus cleaner cart scan this file DF5D40.tmp ???
why do you think this is a “msn virus”? maybe have you googled for it? every explanation is appreciated, thanx. 
it only affected msn and many of my contacts on msn are having the same problems
RPC error is generally related to other antivirus present or, at least, firewall blocking.
Anyway, RPC error is most likely correct by this procedure:
Go to Control Panel > Add/Remove programs > avast! antivirus > Remove
Then choose Repair function in the pop up window (Repair).
If this does not help, can you uninstall / boot / install / boot again?
a brief search with ixquick has found only some japanese pages: the automatic translation says only that DF5D40 is related to java codes, don’t speak nothing about msn…