Old PC, but hitherto very reliable, AMD Athlon XP 2000+, 2.5Gb RAM, 40Gb ide drive, clean XP Install on 10Gb partition (no progs loaded yet), dvd-rom drive, nVidia basic graphics PCI card, PCI sound card, PCI USB2 card. PSU renewed about a year ago. CMOS battery new.
This problem only occurs from cold. On power-up, the POST does its thing, and the Windows XP logo screen (with blue flashing dashes moving across a box) comes up. At this point, nothing happens, except the dashes continue crossing the box, for at least 5 minutes. If I use the reset button at this stage, the POST comes up again, and after the drives have been detected, a message appears saying that 'Windows did not start successfully', and asking me to select from Start in Safe Mode, or Start Normally. If I select Start Normally, XP indeed starts OK this time. But if I select to Start in Safe Mode, it doesn't start it.
Once Windows XP has started, and I shut it down, then power up again, XP proceeds to start successfully, first time.
So, could this be some sort of component problem or electrical spike from PSU or other?
(The 40Gb drive was originally used as a backup, and had no OS, and boot up was from an 80Gb hdd, partitioned in two equal parts, keeping OS and progs on one with Data on the other. This drive was in use when the problem first appeared, and has been completely disconnected for the purpose of eliminating it as a possible source of the problem. This drive had also undergone a clean install on the original OS partition, reformatting as part of the process, so no 'double OS' conflicts there).
All PCI cards have been removed and contacts cleaned, as has the interior generally.
I perhaps should also add that after this problem first appeared, I put up with having to reset for a while, until one occasion when, after a few minutes work the PC crashed, starting a lengthy investigation up a steep learning curve, eventually requiring the use of System Restore. I might also add that the POST restarted of its own accord even before the XP logo screen appeared until recently - it is only since yesterday that for some reason I've consistently reached the XP logo screen scenario.
I know this is a long post, but hope I've covered everything!
Hope someone can help with this.