There are a lot of possibilities that would cause this, but it looks like you've already tried a few. Based on my experience, there are several possible causes.
Precursors
Make sure your hard drive is being detected in the BIOS. You can verify this during POST, or in the BIOS.
- During POST, press the Pause key and you should be able to see your boot devices such as the HDD and DVD/ROM.
- If looking in the BIOS, your devices will show in "Standard CMOS features".
Possible causes
- BIOS configuration issue.
- Bootloader (MBR) is damaged or misconfigured. This is more than likely not the problem because you would get an error like
BOOTMGR is missing
.
- Failing hard drive with bad sectors (particularly where the bootloader is located).
You mentioned that you have the same issue with 2 hard drives, but they both have windows on them? It's also important that windows was installed with the same hardware.
The BIOS can be a mystery a lot of times, and many of the settings seem cryptic. I recommend you take these steps and after each step try booting normally.
- Make absolutely sure you don't have ANY other bootable device other than the HDD, such as a USB drive, connected to the computer.
- Set your hard drive as the first device in the boot order.
- If you have an SATA/IDE drive, make sure the CMOS setup in the BIOS has SATA mode set to IDE. If you've got a newer drive or an SSD, it should more than likely need to be AHCI (Advanced Host Controller Interface). AHCI mode will only work if your drive supports it and the drive is installed/enable in Windows.
- Reset the BIOS to factory defaults, by choosing that option in the BIOS.
Do not open the chassis of the computer if it is still under warranty
- Reset the BIOS/CMOS by unplugging the computer from power, opening the chassis, and remove the CMOS battery for 15-20 sec. It is round and flat.
You've already ran windows startup repair, which in my experience does a pretty good job of repairing the bootloader. But since it didn't work, you can try these steps.
- Boot from your startup disc again.
- Instead of startup repair, choose command prompt.
- At the C:\ prompt, run
cd boot
.
First, run bcdedit
to look at the boot configuration.
- Look at the settings for "Windows Boot Manager".
- Verify that
device
is set to partition=C:
as shown.
- The
default
setting should also show {current}
as shown. It may not say this however when booting from the DVD.
- Otherwise, you may need to do
bcdedit /set {bootmgr} device partition=C:
If your configuration looks different than this leave a comment and I will update the answer to fit your scenario.
If all looks well, you can try this approach.
bcdedit /export C:\SAVEDBCD //backup your bcd file
Bootrec /fixmbr
Bootrec /fixboot
Bootrec /rebuildbcd
Since you've already tested with a different HDD, I won't go into a failed drive scenario.
Other resources that may help:
Error message when you start your computer with a non-system disk
BCDEdit Command-Line Options