If you have another system D/L a copy of Hiren’s Boot CD burn it and run Mini-XP off it at boot. You’ll be able to access your local HD and browse to your Windows\System32 folder and either rename both “aswSP.sys” & “aswRvrt.sys” or delete them, those were the files on my systems that Safe Mode would stop at when trying to boot, once I deleted them I was able to get a normal boot after then Uninstalling Avast v9x first through Windows Add Remove Programs then booting to Safe Mode and running Avastclear.

Hiren’s D/L Link: http://www.hirensbootcd.org/files/Hirens.BootCD.15.2.zip