|When you install a hard drive that has a Windows installation that was installed on it when it was connected to one mboard, then remove that and connect the hard drive with the same Windows installation on it and try to boot from that hard drive when the drive is connected to a different mboard, if the hardware on the two mboards is more than a little different, then often XP will NOT load normally.|
In that case, you need to do a Repair installation of XP procedure, which will not delete the data you have added to the partition Windows was installed on
You need an XP CD of the same version as on the hard drive - Home or Pro.
You use the Product Key that is on the official Microsoft label that was on the case the original mboard was in, or you use a program such as Keyfinder to find the Product Key the Windows installation is using BEFORE you disconnect the hard drive from the original mboard.
However, if the original mboard was one for a brand name system, you probably can't use the XP Re-installation CD that came with that brand name system with anything except the same original mboard and it's brand name system bios version.
If you have any hard drives on the computer that are larger than 137gb manufacturer's size, the XP CD must have SP1 or later updates integrated into it.
Regular Microsoft XP CDs have SP2 or SP3 printed on them if they have those updates included. All the regular Microsoft XP CDs that have SP1 updates included that I've seen DO NOT have SP1 printed on the CD, but the volume labels - the labels you see for the CD in Windows - for CDs with SP1 updates included are different from those with no SP updates at all - you can search using that volume label to determine whether it has SP1 updates or not.
XP re-installation CDs that come with brand name computers usually have SP2 or SP3 printed on them if they have those updates and they may have SP1 printed on them if they include those.
If your XP CD has no SP updates at all, you can make yourself a "slipstreamed" CD (preferably a CD-R) that has had the SP3 updates integrated into the original contents of your CD, and use that to install Windows by booting from it, along with using the original Product Key.
How to do an XP Repair installation step by step:
You will need to load all the drivers for the changed mboard after Setup is finished.
If your Windows CD does not have SP1 or SP2 or SP3 updates included, and you updated the Windows installation to include SP3 updates, you may have to install SP3 updates again to get it working properly. SP1 or later is required for USB 2.0 and hard drives larger than 137gb (manufacturer's size; 128gb in Windows and most bioses).
You may also need to re-install some of your Windows Updates.
XP doesn't have the drivers built in for most things that first came out after XP was first released, circa 2001, and it doesn't have some of the drivers built in for things made before that.
This also applies when you have run a Repair installation of Windows if the mboard is different than the one the Windows installation was originally set up on..............
Whenever you load Windows from a regular Windows CD (or DVD) from scratch, after Setup is finished you must load the drivers for the mboard, particularly the main chipset drivers, in order for Windows to have the proper drivers for and information about your mboard hardware, including it's AGP or PCI-E, ACPI, USB 2.0 if it has it, and hard drive controller support. If you have a generic system and have the CD that came with the mboard, all the necessary drivers are on it. If you load drivers from the web, brand name system builders and mboard makers often DO NOT have the main chipset drivers listed in the downloads for your model - in that case you must go to the maker of the main chipset's web site, get the drivers, and load them.