HI poppy

assuming that the drive's jumper was in correct position, did you auto-detect the hardware?try autodetection and see if it can be detected. Take note that it has different jumper settings for a "master" and "slave". If you did this correctly and autodetect the drive and nothing happens, then you probably got infected by a virus. If your Harddrive is older than your BIOS, it should be detected by the BIOS.