So, apart from the TV card I just about got my "spare" machine)(Celeron 2600, WinXP, 512K) running for daughter to take away to Nottingham with its original 80G hard drive and her original 80G hard drive in it as a slave so she or a techie friend can retrieve all her data and settings at thier leisure. This left me her former slave 80G drive as a spare.

Just before she left she was doing a bit of internet banking and said my main machine (that she was using) was behaving badly, but she is an absolute albatross for computers so I ignored....

Hardly was she out of the drive than I started getting Fatal Exceptions OE and OD (and a few others, as time wore on) mainly when trying to send in Outlook. It got to the stage that the machine was unusable. This is my main machine that runs my office. AMD2400, W98SE, 512, 80G hard drive and a 160G slave for "stuff" running as D 'cos W98SE won't let me make it list after the partitions on the 80G.

This machine was set up with OS and other programs on C partition, and other partitions E, F, and G - E for a backup of the OS, F for data (including the actual current psts for Outlook, and the install files for all downloaded programs), and G for backup of data. I also use a DVD writer to back things up and had last backed up all documents and psts on Dec 15.

Use another machine to do a bit of rummaging on the internet. It looked as if the problem is likely to be memory (the addresses that come up with the fatal exception are memory addresses) or mother board. All computer shops shut so can't take memory to have it tested.

I used Acronis to restore the OS to as it was running stably (well, stably for 98SE) in June. That takes about 5 minutes. It was OK for about half an hour until I tried to send in Outlook. Those two exeptions were back big-time and Outlook was unusable. Therefore it wasn't OS and must be memory or MB.

Use Acronis to make a clone of all partitions of my main drive onto the spare 80G just in case. Takes the damned thing 6 hours!!

Very computer-savvy friend has a look. Agrees might well be memory or motherboard. It just happens he has a spare AMD and motherboard with memory in at home, so I drive to Lewisham to borrow it. He has no drivers for it (bum).

Put his board and bits in my case, it pretty well boots off my original 80G drive (once I have figured out that I have connected the front USB ports wrong) and I start hunting for drivers etc. I get nowhere with the PCI drivers but most other bits I sort of get working - and sod me the bloody fatal errors re-appear so badly there is no point in continuing. Therefore it wasn't memory or MB since both have been changed. Must be damaged drivers addressing wrong bits of memory.

Put my motherboard back with original drive, planning on format C and re-install. Original hard drive fails. Does not go round at all. Thank God for that clone as other backup bits are scattered among manybackup CDs and DVDs.

Format C and E on the clone (actually do it setting that drive as a slave on a spare machine), put clone in main machine (which I have in the meantime put into a nice small neat case in place of the old full size ATX case, since the MB is microATX, PSU almost too big to go in, can't get the mask for the I/O on the rear panel to fit, etc, going to need a USB hub when all is well), re-install Windows. This fights me every step of the way, failing to find files, reporting that one of my DVD drives (the new dual layer combo drive) is not working, telling me that various things are not valid W32 application, etc, etc). Get it up, install office, Outlook won't run. Uninstall Office in order to reinstall. Installation stalls and will not resume. Guess what? Those damned fatal exceptions OD (at 0028:???) and OE (at 0096, I think) are back.

Put Office on spare machine and copy the current psts so I can work if I ever get the time, most clients out of the loop for Xmas-NewYear. Seems OK but I'm a bit worried about running Office 2000 in MinME on a PIII933 with 512 memory.

Rip machine to bits. Discover I have the optical drives the wrong way round set master to slave and slave to master, format C and reinstall. Install Windoze. Goes well this time, leaving Win disc in one optical drive and using the other for drivers/programs/utilities/etc and the Win disc goes and finds drivers and stuff (why is it always secur32.dll and vserver.vxd and a fe other usual suspects that go missing) when needed.

As of late last night I have everything except Office in, and have only seen a few fatal exceptions on the way (alas, they look like the same ones) and the machine seems pretty good for surfing, playing music, watching films, etc, and I am terrified to install Office in case it all falls over and I ahve to start again or buy a new machine.

I think I might just install Word on this machine and leave Outlook on the other one. I haven't seen those fatal exeptions since last night (touch wood).

Which brings me to the point of the story.

What the hell could be causing those fatal exceptions? I never had them until boxing day, and they have now been present on two different C drives, two different motherboards, two different sets of memory, four installs of the OS. The PSU is pretty huge, a 450 watter to run a dual layer DVD re-writer, a CD re-writer, floppy drive, 2 hard drives, a Zip drive on the USB and nothing else yet, so I figure I can rule out PSU issues.

Baffled!