Help! Puter took a dump while scanning

Hi All Back again, lol. Boy since I got the trojan Avast has been really acting up. OK this is the latest: Today I was doing some house cleaning -
Emptyed the cashe on i.e 8 via tools and reset it empty on exit. rebooted
Did a system defrag - rebooted

Avast seemed to be using to much k’s on reboot and jqs,iexplore sychost was to with nothing open so as the virus was hidden in java temp files I decided to disable jqs.exe.

Disabled jqs.exe from control panel and puter seemed to be responding well.
Decided to run Avast custom scan to make sure everything was clean and as soon as it started to run :o Blue screen :cry: Said hardware or software drivers cased the problem ???
turned off the puter and rebooted and it opened with avast scan ::slight_smile: closed it and reopened avast to run scan again but it did not seem to be scanning correctly :-
Took 13 min? normally 45-85min
7-16 kb per sec. but was moving slow
on completion it scanned 18GB??? of files Daaaa! in 13 min???

Virus corrupted Avaast the first time and I reinstalled it, do I need to uninstall again? Don’t think it’s scanning. Ran microsoft safety scanner took 45 min and scanned 800k files (Normal)