Unable to install msi.exe programs

> I may have deleted the windows installer. I have
> downloaded several programs that are msi.exe. I get a
> message pop up that says to contact the vendor to make
> sure it is a valid window installer package. They are.
> Any step by step instructions to fix this ( I am a real
> novice)?
>
> Also get a pop up that says S32EVNT1.LL AND SYMENT.SYS
> DO NOT MATCH. I am at a loss with that one too.
>
> Any help will sure be very much appreciated. Please email
> me at aldir@ix.netcom.com It actually took me 3 hours
> just to find this newsgroup. That tells you how computer
> ignorant I am.
>
> Thanks!
>
> Tony D