??? hi can anyone help i,m using avast 4.7v home ,the free download… the problem i,m having is it keeps asking me to restart my system , to date i have done this 20 times then got fed up and turned the restart setting off, can anyone tell me why this keeps happening please … ps i have uninstalled avast about 4 times now and re installed but it maks no diffrence HELP… 
Welcome to the forum.
Maybe this will answer your question:
http://forum.avast.com/index.php?topic=28199.0
Operating system restart needed by avast message could be solved, in some systems, by deleting the file \setup\reboot.txt
If deleting reboot.txt doesn’t stop the requests for reboot check this:
Check this registry entry (right after computer restart):
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager, if it contains “PendingFileRenameOperations”.
Check its contents and if there’s only “reboot.txt” from avast4\setup folder, delete PendingFileRenameOperations, don’t delete any other key.
Back-up (export) the registry key before you edit/delete, just in case.
Post again if this does not help you.
Again, welcome to avast forums.