I have a Gateway win 7 machine that was having video issues, I installed a PCIE video card and it didn't work. I removed it and ever since on boot the computer says Missing operating system. I have removed the card, reset bios to no avail. I put disk in another machine and it reads perfectly and ran a disk check and virus scan and disk seems fine.
I have tried many other things, but this seems to be the esentials. Drive shows up in Bios and as primary boot device and their were not errors on chkdsk part of scan, so I am at a loss.