Just for clarity: You can boot Win98SE on the same HDD connected to the same controller but not WinXP? Or are you using another adaptor/HDD to run Win98SE?
How is your HDD formatted when installing XP?
Edit: If it's not the same HDD try disabling the Win98SE HDD in BIOS during WinXP install and (at least) first boot.

I'm assuming its just the one HDD namely the WD10EZEX
How did you partition the Hard drive?

For best results I'd recommend using Fdisk as it limits partitioning options to things 98 and XP understand.
You'll want a WinME boot disk just for the partitioning as it has the updated Fdisk with large disk support.

If your just using XP's inbuilt menu to boot between 9x and XP I'd recommend the following partition layout:
Primary Partition - Fat32 (however big you want your Win98 drive) Remember to set to active!
Extended Partition- Rest of the drive
Logical drive - Upto you, you can have one large drive for XP or I would create 2
D:\ Fat32 and accessible between both OS's
E:\ NTFS WinXP, (Putting it at the end means your drive letters wont move around as well)

Thanks everyone, I will try out these things when I get home 😀

chinny22 wrote on 2021-04-28, 10:55:

I'm assuming its just the one HDD namely the WD10EZEX How did you partition the Hard drive? […]
Show full quote

I'm assuming its just the one HDD namely the WD10EZEX
How did you partition the Hard drive?

For best results I'd recommend using Fdisk as it limits partitioning options to things 98 and XP understand.
You'll want a WinME boot disk just for the partitioning as it has the updated Fdisk with large disk support.

If your just using XP's inbuilt menu to boot between 9x and XP I'd recommend the following partition layout:
Primary Partition - Fat32 (however big you want your Win98 drive) Remember to set to active!
Extended Partition- Rest of the drive
Logical drive - Upto you, you can have one large drive for XP or I would create 2
D:\ Fat32 and accessible between both OS's
E:\ NTFS WinXP, (Putting it at the end means your drive letters wont move around as well)

Oh sorry I should have spoken more clearly about the drives, both separate to avoid hassle, one HDD for 98, and one for XP. I didn't partition, I just let the install format to NTFS (tried full and quick) and use the full raw space to create one partition or however it does it. I also tried setting boot order either way for CD and HDD and I get the disk read error (configuring each to match the hardware too, also tried auto) on reboot once the CD copied files over as a result. I am not fully sure about this one, very interesting, I don't think the HDD is dead because I just got it new of course, but there is a possibility. Any other factors that could get this install working? I also swapped between multiple optical drives (currently am using a generic modern one with an IDE adapter, works great). On the same machine I once was able to install XP on a native IDE CF and it worked but obviously was slow. Maybe I have a bad ISO image? It is SP2 but I am curious if I should use my SP3 disc as I used that one my CF at one point. I am not fully sure what factors play into this but I do know that there has to be an explanation for it all. Thanks everyone.

Maybe your hitting the 48bit LBA limit? You shouldn't if your installing a SP2 or SP3 version but never know
Try creating a partition 128GB or smaller. (personally I like 10-20GB for a games rig) anyway and see if setup gets any further.

What was the HDD you installed Win98 on, did it use the IDE to Sata adapter? always a chance it just doesn't like that particular HDD

But you shouldn't need raid drivers or the like, XP supports IDE natively and the adapter is invisible to any OS, as far as it knows its just a IDE drive.

chinny22 wrote on 2021-04-30, 09:50:

Maybe your hitting the 48bit LBA limit? You shouldn't if your installing a SP2 or SP3 version but never know Try creating a part […]
Show full quote

Maybe your hitting the 48bit LBA limit? You shouldn't if your installing a SP2 or SP3 version but never know
Try creating a partition 128GB or smaller. (personally I like 10-20GB for a games rig) anyway and see if setup gets any further.

What was the HDD you installed Win98 on, did it use the IDE to Sata adapter? always a chance it just doesn't like that particular HDD

But you shouldn't need raid drivers or the like, XP supports IDE natively and the adapter is invisible to any OS, as far as it knows its just a IDE drive.

The HDD is the same as the 98 HDD, they both use an IDE to SATA adapter. I also tested a 128gb SSD but no go for that either. I might just try the SP3 when I get home and see if that works out.

chinny22 wrote on 2021-04-30, 09:50:

Maybe your hitting the 48bit LBA limit? You shouldn't if your installing a SP2 or SP3 version but never know Try creating a part […]
Show full quote

Maybe your hitting the 48bit LBA limit? You shouldn't if your installing a SP2 or SP3 version but never know
Try creating a partition 128GB or smaller. (personally I like 10-20GB for a games rig) anyway and see if setup gets any further.

What was the HDD you installed Win98 on, did it use the IDE to Sata adapter? always a chance it just doesn't like that particular HDD

But you shouldn't need raid drivers or the like, XP supports IDE natively and the adapter is invisible to any OS, as far as it knows its just a IDE drive.

Just tried SP3 and that was a no go too, disk read error on boot with HDD. Any other factors possibly? Later I will try to install the OS on a 10 GB partition just to see too

The small partition works, I wasn't too sure but like everyone was saying before, just make a smaller partition so I just went with 10 GB and it boots up now. Thanks everyone 😀