error message

Removed HD from old system.It was working fine.Installed in new system.Both systems are Win 98.Get error message :invalid drive specification.Did a FDISK.Found that partition was created and active.Tried FORMAT c: .Received the error message:”invalid drive specification.Can not ger to BIOS setup because thre are no instructions or prompt to do so.This is a GATEWAY 2000 computer.How do I get to the BIOS?