need major help PLEASE

I just had a post that I ran pestpatrol free scan and then proceeded to get rid of what it showed as problems. Only now I went to scan and I can't! It says it is unable to communicate. I double checked that everything was corrected and went through the hardware thing in control panel. Everything is fine. I then realised that pestpatrol had brought up TWAIN and I had deleted what it showed as a problem without even thinking that my scanner needs TWAIN (I don't know why - not that versed in this). So, I get my disk for my scanner thinking 'no problem', I'll just reinstall and that will replace anything I messed with. WELL, now I get a message about Windows Installer that I'm either in safemode (I'm not) or something else. I checked my computer, I have Windows Installer on my system! It is even included in the software that came with the scanner. So now I can't scan and I can't re-install the software because of whatever is up with WI.

Argh!

 

I have another current post with some other problems I'm having - don't know if reading it may give anyone an idea of what's gone wrong. The other post is at http://forums.majorgeeks.com/showthread.php?t=44343