|Sounds like the system cannot find any boot code on the hard drive, which may mean the hard drive has failed and needs replacing. To confirm this, test the drive with SeaTools for DOS diagnostic software which can be used to test any brand of hard drive.|
Click "Downloads" on this page and download the SeaTools for DOS ISO file & save it: http://www.seagate.com/support/down...
Now download & install IMGBurn from here: http://filehippo.com/download_imgburn/
Use IMGBurn to create a CD from the SeaTools ISO file, then boot your faulty PC from that CD to load SeaTools.
Select the hard drive that needs testing and run the "Long" or "Extended" test on it.
If it says "Failed" in any of the test sections, you need a new drive.