Best thing I can suggest here hun is to start disconnecting non-critical stuff before running the install. If it's a device or card causing the BSOD then you may find after you pull it the install will work. One thing I'd definitely do (if you can) is remove all but one of yer memory sticks. If it fails with only one stick in (& you've removed others) then swap it over & try again.
I'll be surprised if it's a dodgy memory stick though cos you said 98 works...
If the installer runs after any of this, then once XP's on there you can always re-connect the bits you've pulled one by one setting each up in XP individually (painful, but the best way).
Failing all this, start disabling non-critical stuff on the motherboard... soundcard, networking etc... (as with cards, you can add it back in later).
Depending on the BIOS in your PC, you may have some BIOS presets you can load... some of em have like "Failsafe" & "Optimum Performance" settings you can use... If you have these, try em (but remember to note down which settings you are using beforehand, so you can set it all back how it was if you need to)...
Sorry if this is all a bit vague... Trial & error is really the only way to get to the bottom of stuff like this...
If I were you, I'd do the following...
1) One big change between 98 & XP in terms of motherboard design which I've seen cause problems is ACPI power management (in 98 time there was onyl one power management standard... APM. ACPI came later). I've seen problems, specifically BSOD, when installing Operating systems relating to this... If you can find it in the BIOS, flip between APM & ACPI trying the install each time... this may crack it.
2) Personally, I could not be arsed pissing about with disconnecting devices etc... I'd take the path of least resistance & Install Windows 2000. In my experience it has fewer hardware-related quirks, is "almost" as new as XP, and I've not found any software which works with XP which won't work with 2000. I also think it looks better... XP's GUI looks like it was designed by schoolkids...
Sorry I haven't given you an absolute answer there, but hopefully a few pointers which will help you get it sorted.