Hello,
I installed Avast Free today on Windows Vista 32bit and I now receive a STOP 0x00000007b BSOD when I boot. I cannot enter any of the safe modes or restore last known good configuration. The last file I see when trying safe mode is aswrvrt.sys. I ran FRST through the recovery console and I attached the logfile. I modified my username in the file so as to only display my first name, so if your fix involves anything where the user path needs to be corrected, please let me know.
Thanks!