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Windows 7: Corrupt W7 Installation - "Error Loading OS" message

30 Oct 2009   #1

Windows 7 Ultimate
Corrupt W7 Installation - "Error Loading OS" message

I checked the forums and could not find my specific issue.

The other day, I successfully installed Windows 7 Ultimate (full version, clean install) on my primary "C" partition and everything worked. Now, I believe I have a corrupt OS. When I attempt to boot normally, I receive an "Error loading operating sytem" message. The Windows 7 installation CD is detected, and begins booting, but following the "loading Windows" screen no options are displayed.

Here is what I did to cause this issue:

-I had an old external drive not compatible with W7, so I decided to try and install XP onto a secondary partition.

-In order to create this partition during the installation, I deleted my "E" partition which I had previously locked with BitLocker. I left my "C" partition (System Rese) and "D" partition (with Windows 7) in tact.

-I began installing Windows XP. Upon reboot, I received my first "Operating SYstem Not Deteced" error.

-I tried booting from my WIndows 7 CD to see what was going on, but following the boot from the CD, the installation program stpped running before any options were displayed. This occured after the "Starting windows" message was displayed.

-I tried booting from the Windows XP install CD. This CD boot properly. I deleted the partition I had attempted to install XP on.

-I tried booting normally, and "Operating SYstem Not Deteced"

-I tried booting from the WIndows 7 CD again and "Operating SYstem Not Deteced"

At this point, I am considering loading from the XP CD and deleting all partions with hopes for a fresh Windows 7 installation.

Anything else I should try before deleting my partitions?

I am not even sure this will work, but any ideas / insight would be greatly appreciated.

Thank you for your time -

My System SpecsSystem Spec
31 Oct 2009   #2

7600.20510 x86

You can not install any version of Windows to an external device or drive.

To fix: Detach external drive from system. Boot to Windows 7 DVD and run startup repair.

Startup Repair
My System SpecsSystem Spec
31 Oct 2009   #3

Microsoft Community Contributor Award Recipient

Windows 7 Ult x64 - SP1/ Windows 8 Pro x64

Follow torrentg's suggestion to repair the boot files.

It's best to install OS from the oldest to the newest, XP first then Win7.

But installing XP after Win7 can be done.

Check this Seven Forums tutorial, when you want to install XP with Win7 already installed.
Dual Boot Installation with Windows 7 and XP. Method Two.

By installing XP after Win7 was installed it disrupted the boot file.
My System SpecsSystem Spec

31 Oct 2009   #4

Windows 7 Ultimate

@torrentg, i wasnt trying to install to an external device. I was jsut trying to pull files off an old zip drive not compat w/ win7

@Dave76, thanks for the link

Appreciate the responses.
My System SpecsSystem Spec
31 Oct 2009   #5


-I had an old external drive not compatible with Windows 7, so I decided to try and install XP onto a secondary partition.

That is a major NO NO.

If you want to DUAL boot and have XP and Win 7 on the same computer.
1. install XP
2. while in XP insert the DVD an Installed Windows 7. (default will be Windows 7). if you want to change when you boot you hve 30 s to chose the OS you want to boot into.
1. Install Windows 7 on Primary HDD #1. reboot to make sure all is OK.
2. shut down the system. removed the Primary HDD #1.
3. Install Primary HDD #2. install XP.
My System SpecsSystem Spec

 Corrupt W7 Installation - "Error Loading OS" message

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