I have very limited knowledge in computer hardwear so your going to have to take things slowly. On thursday morning the computer was running fine, viruses scans checked out firewall was on and the only connection to the internet was the forums being opened. Thursday afternoon i got home, turned the computer - the first screen appeared, the one that checks the IDE Drives - second appeared, the one that checks the PCI Devices listening Than the message of Disk boot failure, Insert system disk and press enter Now i researched this problem first, and attempted to fix it myself, some of these solutions were: - Accessing the bios on start up, and checking that the hard drive was the first in the boot order. - Just time, let it stand for an hour and it didnt pass the error message I had no choice but to put the system disk in, upon doing so while it gathered information the following occured SysC810.sys is corrupted, restarted the computer and ran the disk again Sym_hi.sys is corrupted, restarted the computer and ran the disk again UsbHub.sys is corrupted, restarted the computer and ran the disk again It finally completed the gathering the required information, than gave me the option of formatting or repairing. On choosing either it came up with a further error message of Windows cannot find a hard drive I removed the ram stick(512) replacing it with a 256 from another working computer. It returned the same error. I tried the 512 in the other computer it ran fine. I removed the hard drive (120 Gb) it runs on a sato cord. Replacing it with a 60Gb one which plugged into an IDE connector. Runnning it same error appeared. Im out of ideas, and looking for any advice. I have a gigabyte pent. 4 titan series GA-81848P(-L) motherboard. thanks