Deleting things can usually be done in Safe Mode, or even easier, from a command prompt...

Remember though...You don't want to "Delete" programs, you want to UNINSTALL them.. That's an entirely different thing. Please make sure you're referring to "uninstall" programs, not delete.

You haven't mentioned whether you simply ran the "Disk Cleanup" option to cleanup system restore. From there you should be able to let the computer remove all System Restore points except the most recent.. Performing this step should eliminate enough space for you to work with.. (Click on Start-All Programs-Accessories-System Tools-Disk Cleanup.. Once that loads, click on the 'More Options" tab, then select the "Cleanup" button in the System Restore section.)

Hope this helps.