I am not an engineer so I cannot supply you with technical specifics. Also keep in mind that there is an ongoing debate on this subject matter, and I have no intention of opening that debate, nor will I participate. One of the main reasons for seperating Roms from the HDD, is because during certain types of data I/O, the ROM must slow the transfer rates .I/O will default to the slowest item connected on the same IDE channel. There are any number of scenarios that you can see if you use some imagination. Depending upon which HDD your programs,O/S, Page file etc are placed and where data is being accessed from, have significant impact on the overall performance of your machine. I am sure that , to configure a machine to create the possibility of more bottlenecks than is necessary, is a basic mistake. I understand that your machine has been working fine for your purposes, there is always the philosophy " If it ain't broke don't fix it" Generally accepted protocol says not to use your configuration. BTW I also suspected there was some link between this and your original problem. Since you have solved your problem, I may be wrong.