Back up anything you want to keep from your computer.. pictures, music, documents, drivers, software install files, etc. Then proceed to put your Windows install disc in and boot from it. Follow the instructions to format your drive and reinstall Windows. After you are done, run Windows update and install up to date anti virus software. Now reinstall your software and copy your files back to your hard drive. I have to say though, I am running Windows XP with both Nero 6 and Roxio 8 installed without any problems. I have been running the same XP install since May 2003.