First off windows has something called the HAL, it is the hardwareabstraction layer, each one is different 'cause you have different hardware and the kernl talks to the hardware throught he hal.
You can xfer all your old data to a folder on a new install, sorry but all programs will need to be reinstalled. Dont' forget to back up ie favorites and your email settings and mAIL if you have pop3 email and use outlook or outlook express, or if you use outlook or outlook express for internet email. Also back up any databases like quicken / ms money etc.
there is a slight chance you can use the old install, i can tell you how to do it, it is not recommended.
install xp on the new computer ( probably SATA HDs) unplug a cd drive or other PATA device . Should only be one on the cable if 2, do not forget jumpers. Hook the PATA hd to the cable on the new pc. Plug her in and turn her on. When the pc boots up it may detect the new drive and try and boot from it. With win explorer create a folder called old data. Then find the old HD in windows explorer and start cutting folders from the old hd to the new folder called "old data". When you cut and paste, if you get an error like "windows can nor access the file" the cut will bomb. Windows will copy over up to that point , so u have to go back and make the correction to finish the cut and paste. Also cut usuall works from Z to A.
Usually if you get an access is denied you just have to take admin possesion of the folder, no big deal, may not even happen.