I recently took out a 4x cdrom and replaced it with a 16x cdrom in my friends old pentium computer. After I (finally) got the case off, I replaced the drives and set the cdrom as the slave, just like the previous one. Now when i turn it on, I get a hard disk error and I cant get the motherboard to boot from the hard drive. I never changed any settings and i got errors. I thought that I could just replace the two drives and everything would be fine but i cant even get the computer to boot. It gives me a "hard drive error". So i then switched the jumper setting on the motherboard to clear cmos and then switched it back to normal and still got the same error. I dont know what I am doing wrong and i assumed that this would be very easy, but I was wrong. The motherboard is a very old IBM model. The BIOS will detect the drive and it is listed as the 2nd boot device, but i just can't figure it out. Also when i try it with a 4 gig drive it only recognizes it as a 26 mb drive?? What am i doing wrong? Thanks...