Missing OS Loader.

I accidentally posted this in the 'Files' section rather than the 'Forums' section, so I'm sorry for that mistake/double post! D: Admins, if you feel one needs to be deleted, please delete the one from the wrong section.

This might be very common, or it might not be, but from the research I've done, nothing seems to work. After one night I went off my computer, I had just been doing the usual stuff. I didn't do anything unsual or see anything unusual. The next day the computer booted with Startup Repair. I thought this was strange but I let it get on with it anyway. Then it came to restarting my comp and Startup Repair came back again. This is when I suspected something was wrong. I'm running Windows 7 on a Dell Inspiron 560MT. After letting it try again and restarting a few more times, I checked the diagnostic and repair details. These are as follows.

Problem signature:
Problem Event Name: StartupRepairOffline
Problem Signature 01: 6.1.7600.16385
Problem Signature 02: 6.1.7600.16385
Problem Signature 03: unknown
Problem Signature 04: 18
Problem Signature 05: ExternalMedia
Problem Signature 06: 1
Problem Signature 07: MissingOsLoader
OS Version: 6.1.7600.2.0.0.256.1
Locale ID: 1033

So I decided to research into what I could do. Through advanced options and using my installation disc, I got to command prompt and tried BootRec and ChkDsk. None of these seemed to fix the issue. However after restarting my computer it doesn't go into system repair anymore. It comes up with two different screens.

The first one looks like this.

Windows Boot Manager.

Windows failed to start. A recent hardware or software change might be the cause. To fix the problem:

1: Insert your windows installation disc and restart your computer.
2: Choose your language settings, and then click "Next."
3. Click "Repair your computer."

If you do not have this disk, contact your system adminstrator or computer manufacturer for assistance.

File: \Windows\system32\winload.exe
Status: 0xc000007b
Info: The selected entry could not be loaded because the application is missing or corrupt.

After this, it says I can press enter to continue or esc to restart. If I press enter, it shows the second screen, which looks like this.

Windows Boot Manager.

Choose an operating system to start:
(Use the arrow keys to highlight your choice, then press ENTER.)

Windows 7 Home Premium

To Specify an advanced option for this choice, press F8.

However, pressing F8 takes me back to the first screen about winload.exe being missing/corrupted. Inserting my disk takes me back to this screen unless I enter setup to override the priority for the disk to load, and repairing my computer just comes up with the first error seen at the top of my post. I've tried numerous things but nothing seems to work, and I would like to avoid a clean install which would be my absolute last resort. Any help would be greatly appreciated!

Thank you.

 ~Adam