Hi Radarman
Thank you for your suggestion of Registry Mechanic. I d/loaded it and although I have Norton Windoctor, OnTrack "Fix-it" Registry Cleaner and PC Bug Doctor, I decided to register.
I was amazed when, despite running the other utilities regularly, it found no less than 438 spurious registry entries! I thought, with running the other three house keeping utilities, that it would find next to nothing. That's some tool!
Anyway, repaired all the suggested invalid entries and with eager heart, did a test flight on the troublesome machine with FS2004 rather hoping that after such a powerful vacuuming job, the bug might well have disappeared.
Alas, "flying" a B747 on a FSNav4.5 flight plan from Cardiff to Iceland, all seemed well until the a/c was passing FL330 for cruise flight level FL350 and around 100 miles into the flight, some 20 minutes or so after t/off in a smooth climb - suddenly - no warning or anything - a blank BSOD without any error message. Reboot the machine and XP's chkdsk found NO errors or lost clusters on Drive C (operating system) or Drive I (FSims location).
Yesterday, I "flew" FS2004, B747 from Sidney Oz to L.A. - around 15 hours in real time on the m/c which doesn't give any trouble with FS - again on an FSNav4.5 flight plan. It flew all night and went through to "land" this morning. This on W2K with a slower processor and less memory. Also a lower spec graphics card.
My main m/c is a P4 at 3.2GHz, 524Mbs memory, Radeon 9600 Pro, XP Pro with two 160 SCSI drives, 1 serial ATA and 1 standard EIDE. Device manager is clear, the m/c starts up and closes seamlessly which suggests no faulty driver hanging on. The m/c is heavily loaded with various apps, all of which, Flt Sims 2002 and 2004 apart, perform faultlessly. Even Videostudio 8 video capture, edit and DVD-creation is a faultless process. This, as you probably know, throws a heavy strain on every aspect of the architecture.
This bug is maddening. Do you, by any chance, have any other ideas or can you tell me where I might seek some know-how (whether in MS or elsewhere) ? We all know that elusive bug fixing on a computer is akin to the proverbial needle in the haystack.
To close this long spiel - thank you for being there and so helpful.
Bob