i previously installed Fedora Core 2(linux) later formatted it by deleting partition now i have installed WIN 98 SE when i try to install XP Pro after running the OEM AND copying setup files in DOS It reboots the pc then instead of continuing setup the messeage appear under VERIFYING DMI POOL DATA the message is MISSING OPERATIVE SYSTEM this same happens for windows 2000

How are you trying to install XP?

Am confused by: "when i try to install XP Pro after running the OEM AND copying setup files in DOS "

XP should install itself from boot. If it is an upgrade version it will see 98 & upgrade.

If it is a full version it will format & install.

A good guide here:

http://michaelstevenstech.com/index.html

As to the error:

Computer stops at verifying dmi pool data...:

Sorry if I misunderstand your question.