Resolved IE6 to IE7 or IE8 problems

i'm currently running IE6 SP3. i've tried upgrading to IE7 & IE8. in both instances i get the following problem.
(this occurs when i go to open the newly installed IE7 or IE8.)

microsoft visual C + + runtime library.
runtime error.
program:c:\program files\internet explorer\iexplore.exe

this application has requested the runtime to terminate it in an unusual way.
please contact the applications support team for more info.

what does all this mean, & can anyone help me to get IE7 or IE8 installed.

thanks,

johndb.

 

evan,
your advice was spot on.
i tracked the problem down to the add on "google toolbar helper ".
once i disabled this every thing worked fine.
thanks again for your help.

johndb.