The first thing I see is that you're having troubles with .vxd files.

These are "virtual device files" or "helper files" that feed info to other programs and/or device drivers. It's almost impossible to tell what program/device a particular .vxd is supposed to be associated with, except by consulting the source of the .vxd or finding the program that tells you that you need a specific one.

This file type is notorious for being easily corrupted or infected by virus/malware that may have been on any of your machines. That shouldn't be a problem if all your installations are from clean CDs, but many Win95/Win98 installations were from floppies which could have been infected or damaged.

I would assume that you're doing the WinXP stuff all from a CD, since that's the only way I've heard that it comes. If you're using any floppies or other writable media with the other versions, there could be the possibility of file corruption (or infection) on any such "originals" unless you've been very careful. You're the best judge of whether this could be a problem.

WinXP will default at least to FAT32 format on your hard drive, and may try to impose NTFS. A "reformat" will often try to use the same as what's on the drive. Early versions of Win95/Win98 had problems with FAT32, although it should be acceptable for Win98SE(?). There were some rather bizarre effects of the maximum size drives that some Win versions could format - with the result that some older versions could format a volume larger than they could read, and some later versions could NOT format to the max size they could use.

If you're using the Seagate HD software, it should be able to handle anything needed, but you may have to tell it, fairly carefully, exactly which format you want for the "next installation" you plan to use.

I'm not getting any inspired flashes other than that .vxd files are "corruptible" and the several formats that you can put on a hard drive could be a problem if you're swapping back and forth between OS versions.

I don't see anything obvious, but with your first-hand view of your setups, you might find something in the fairly detailed How to prepare to upgrade Windows 98 or Windows Millennium Edition to Windows XP (KB article 316639).

A sometimes helpful (warranty subject to limitations) method is to put error messages you see into Microsoft's Advanced Search engine. There have been quite a number of Knowledge Base articles on WinXP installation clinkers, and you might get lucky(?).

Sorry I can't put a finger on anything more helpful.

John