This problem is caused by previous program you have installed not cleaning
up after itself properly. A file called setup1.exe usually found in the
c:\windows folder needs to be deleted. The easiest way to do this is as follows:
1) Click on START - FIND - FILES & FOLDERS
2) Carefully type in "setup1.exe" (without the quotes).
3) Make sure the "look in" is on the same drive you have windows installed
on. Usually c: drive.
4) It should find setup1.exe in the windows folder. Use the RIGHT mouse
button to click on the file. This will bring up a floating menu from which
you should choose the DELETE menu option.
5) Now try to install again.