It is not real clear what the sequence of events is here and what you mean by "boot up," but did you remember to set in CMOS for the BIOS to check the cd as a possible boot disk? Then, when the o.s. is loaded, you will also have to set the new disk as the boot disk. It is possible that it is looking for the operating system on the old disk and/or on a floppy. Go into CMOS and check to make sure it is set right. (Never having had a SCSI computer, I do not know their idiosyncracies.) Dean Kukral ----- Original Message ----- From: Patrick Roane Sent: Monday, December 27, 2004 12:42 PM Subject: [PCBUILD] western digital Hello, I have an old Dell PII Demension XPS 400 that has a bad hard drive. It is a Western digital 4.36 single-ended ultra fast wide SCSI-3 interface. I didn't know this when I bought a new seagate 8.4 gig IDE which I installed w/the spare IDE cable comming from the mother board. It needs an OS, so I put my win2000 cd (burned and has worked in the past) and it boots up, but than it says "No OS Found. Insert OS setup disk, then press any key" Do I need to reformat the new hard drive using fdisk? any help would be great. thanks- Patrick PCBUILD's List Owners: Bob Wright<[log in to unmask]> Drew Dunn<[log in to unmask]>