I have been having a bad time with an Intel Celeron 1.2GHZ (belonging to my brother-in-law). The checksum error was cured with a battery change. But then, Win98 installation would stop near the early stages. Finally when Win 98 was installed by brute force, MS Office and other software would not install ( the m/c would hang). It was diagnosed as a problem in the CD reader, so that was replaced by a new CD/DVD combo writer. Still some s/w applications would not install, and though XP did get installed, the PC behaved erratically, in that it would sometimes boot & sometimes not. (couldn’t catch any virus with Norton 2005) So the hard disk was replaced, on the advice of the support person. Now when the PC does boot (about once in 15 attempts), it seems to work normally (actually no one dares use it too much, now). I finally checked out the N-E voltage. It came out around 11V ( surely higher than recommended). The support person says that this is the crux of the problem, and that at his workshop the PC was behaving perfectly. My cousin, who has been (after doing a course in PC maintenance) practicing for around 8 years, says that the PC should not malfunction unless the N-E voltage meets or exceeds 25 V. (And one guy actually has no earthing at his place, but his PC seems to work normally !!) He also said to check for loose contact in the power supply to the motherboard. Another thing he suggested was to check out the capacitors (which stick out like sore thumbs). Sure enough, one of then seems to be a little puffed up, but the local support guy laughed it off. Now it seems that I might have to change the motherboard. And it isn’t funny anymore, because I was the person who introduced the support person to my brother-in-law (based on a reference by an old colleague). Any ideas, please ? Junking the PC, is NOT the option I’m looking for.. Thanks in advance.