Hmm... disable Date Execution Prevention on your PC. If you are using XP here is how to do that.
Click on your Start menu, the right click on My Computer and choose Properties from the quick menu.
The system properties dialog will open. Click to the Advanced page. Then in the performance group click on the settings button.
The performance options dialog will open. Click on the Data Execution Prevention tab. Make sure it is set to "Turn on DEP for essential Windows programs and services only."
This is a shot in the dark.
If you are using Vista let me know. You may need to run everything "as administrator". Turning of DEP on Vista is similar but I don't have Vista here so I can't give you step by step for that.