I recently purchased an MSI N460GTX Hawk Talon Attack to replace my MSI Radeon HD4830. I uninstalled drivers, rebooted, then powered down, completed the hardware swap, rebooted and found that I am now getting the Disk read Error, Alt - Ctrl - Del to restart message.
Probably the MBR got messed up during the installation. Hopefully, the problem is there and not HDD complete failure.
You can try to restore the MBR using Windows' repair functions. You will need the Win CD for that.