Trend Mirco.. made my computer crash why?

I bought Trend Mirco for the first time and it would make my computer freeze and i would have to manually shut it down. My computer worked good without the program, i installed since my Norton expired. I talked to them a zillion times with no results they didn't know why the program made my computer slow and freeze. Than after a little while my computer completely crashed. and i had to take it to repair. I cant take the software back...and i exchanged it ..now i don't know what to do with it...should i re installed it or would it do the same thing? They repaired my computer and it works great without the anti-virus but im kinda scared to not have it.

 

I think Norton hasn't been fully deinstalled ...

 

it was...i went to the Registry file and it was gone

 

When they repaired your computer what did the say the cause of the crash was? I suspect you can reinstall TM and it will work as it should

 

Does repair mean they reinstalled Windows, or did they just make the pc boot again? Did it have any malware? If you have Windows 7 you should make a restore point before you try to install again, that way you can recover if things go wrong.