Win2kStartUpHangs

Recently I assembled a PC.P4 motherboard,Celeron 1.7GHz Processor,40GB HDD.It is working fine with DOS 6.22.When installed with W2K Professional,it installs successfully, task manager shows system occupies 96% to 100% of CPU always.When shutdown,it hangs and couldnt start up for the second time.There is this message “Unknown Flash Type” when starting up.
IF it is a problem with W2K how could I install 98 as it says NTLDR not found each time I startup with 98 bootup disk.
thank you.