I agree with the comments about overheating. 63° Celsius does seem high, although that's not unusual for an old Pentium 4 computer. About the Live CD not freezing: the Live CD you are using probably uses the default system graphics instead of the Nvidia graphics driver that you are normally using. So if your graphics card is beginning to fail you would see the signs of it first on your normal OS and not on a Live CD. The music infinite loop, for example, could be due to a failing graphics card as well as the freezing during boot.
My suggestion is to test your computer with a different graphics card, and see if that solves the problem.