Best Buy warranty

[tgxiii]

Does anyone know if opening a computer bought from Best Buy or any other retailer voids any warranties? My friend bought a computer from Best Buy. She opened it up to put a video capture card. Then, recently, her hard drive died out. She still has the warranty for it, but will Best Buy deny it from her because she opened up her computer? Also, links to government regulations concerning this would help, if you have it. Thank you for your time.

[Buzioid]

We bought one from Best Buy a long time ago, and with their 3 year warranty. We upgraded the Video card as well, and they didn't care when it went in for service. But, I do think it might have to do with the type of computer. We had an emachine and they just took our old one and gave us a brand new one that was twice the speed! But, they don't do that anymore with emachines, they will try to fix them instead of just trading for a new computer.