Fess up, you threw the restore CDs away. Thats okay, cause you can get replacements from EMachines. Note that these will simply overwrite any data that is already on the drives. Only with an actual XP disc can you repair your XP installation without losing any data that is on the drive. But, I think you need to more clearly state what you are trying to accomplish. Otherwise the correct answer to your original post is:
1. Create a System Restore point.
2. Use the Add/Remove programs icon in the Control Panel to remove any unnecessarprograms.
3. Right click My Computer and select Explore
4. Delete any unwanted folders/files.
If you manage to screw up any system files, simply do a System Restore.