I have a clients laptop which hangs on start up and in Safe Mode the drivers stop loading at aswrvrt.sys. I have tried system repair tools both off the hard drive and a windows 7 disc. It is an Acer laptop and I have also tried to do a factory reset (both with and without destroying all personal documents) with no luck. I get an error that says it can't complete. I also tried to use Ultimate Boot Cd to go in and delete the Avast antivirus folder off the hard drive because I believe it was an Avast update that caused this problem in the first place. I believe I need to be able to uninstall (rather than delete) the Avast Antivirus program. Any ideas?