is your win xp pro an upgrade or full version? if its an upgrade you have to install windows 98 first and then the upgrade.
its probably best to reformat your drive to have a fresh start and yes you will loose all your files. if you have an extra hard drive laying around why dont you try installing your OS on there and put the 120gb seagate as a slave. maybe within windows you will be able to browse the seagate and get any files you want to save.
when you reformat the seagate i suggest you make some partitions.
o so you can back up your files. then just reformat. install 98 then xp if its an upgrade. or just install xp. and make some partitions!
maybe this will help you out also
http://www.blackviper.com/Articles/O...tallxppro1.htm