How to Repair a Warped CD?

Only one way I found works well and 100% every time without any risk.
Put the disk on a flat solid and hard surface like a kitchen work area.
Pour boiling water from a kettle all over the disc.
Wait for the disk to cool down. (this happens fairly quick)
The water distributes the heat evenly all over the disc and because CD's are manufactured so precise, they return to their original shape when even heat is applied.
And uneven heat like the sun or uneven presure will warp them easily. When I heard this the first time I was sceptical. But I was very surprized when I tried it. It works!

CDs are partly made of plastic, and if you accidentally leave one on your dashboard or in your car trunk (and you'd only do that by accident, right?), it could get more warped than your taste in music. Since CD players prefer perfectly flat discs, that's a problem--but one that may be fixable.
1. Inspect the CD for cracks. If the airtight seal is broken, then the aluminum inside the disc will corrode regardless of whether you can get the CD flat again. (See How to Restore a CD.)
2. If the CD isn't cracked, clean it carefully with a soft cloth, making sure it's free of debris.
3. If the CD is only slightly warped, try sandwiching it between two pieces of 1/4-inch (6-mm) window glass and pressing it beneath a 10-lb. (5-kg) stack of books for two or three days.
4. If the heavy books alone don't work, try warming up the disc to soften the plastic first. Place the disc in a zipper-lock plastic bag and immerse it in 100°F (38°C) water for 5 minutes. Repeat the book pressing.
5. If you succeed in flattening a warped disc, it's a smart idea to make a copy of it, in case the airtight seal was broken and the disc later starts to corrode.