Might try reading
this thread for some suggestions.
Also make sure you have all necessary
Windows updates and that all DCC ports are clear. Disable any firewalls/routers you have (for now) and see if it crashes then.
Unlikely, but disable any scripts that are running with
/remote off before receiving a file/chat session. SysReset script is known to cause issues.
It's also possible that you've got a virus (twice now) - If you use DCC a lot for file sharing then it's more than likely. Try out some of the following AntiViruses:
SwatIT AVG Trendmicro Online Scan The Cleaner You may want to read
http://www.mirc.co.uk/help/virus.html or
this post for further virus advice.
You may want to run a
Search of the Forums, I believe people have had similar problems before. For best results, expand to 'All Forums' and 'All Posts'. Use various different search terms, not just one.
Make sure you wait at least 1-2 weeks for other suggestions that may be made in this thread before thinking about reinstalling Windows again. If nothing here helps you may want to go to Microsoft's
Support site.
G'luck!
Regards,