This could be the result of a damage disk, a failed download or a virus.
You may want to contact the author of this installer to obtain a new copy.
It may be possible to skip this check using the /NCRC command line switch (NOT RECOMMENDED)
If you have this error then you can go to Start>Run>cmd (or command for Win98 or ME)
and then go to your destination folder and run your setup (or any exe file) like this:
for Example: SharpDevelop_18.104.22.1684MayBetaRefresh_Setup.exe /NCRC