I have recently bought a 250GB Maxtor HD. I installed it as master one IDE 0 along with my old 120GB drive as slave. I put a fresh copy of windows on it (not dual booting). I kept my old windows install on the old HD until I get everything up on the new one. Everything works fine unless I transfer files between my old HD and the new one. The system will lock up for a few minutes, and stutter along until the files are transferred. I can't do anything else while transferring files. I have the new HD set to Ultra DMA6 and the old one on Ultra DMA 5. Also, Disk management list the old HD as "Active" and my new HD as "System". Anyone know what could be causing this?