Windows 7 No Boot, Error 13:Invalid or unsupported executable format.

Hello,

Welcome to Microsoft Community. I will certainly help you with the issue that you are facing. To understand the issue better, I would like to ask a few questions.

1. What is the make and model of your computer?

2. When was the last time it was working fine?

3. Have you made any software or hardware changes recently?

4. Is the computer set for a dual boot? Are you using any third-party software as a part of boot setup?

This issue occurs when you use any third-party software to boot the operating system. Mostly seen in the systems using a software for double boot. You may refer to the following Microsoft link for more information.

https://social.technet.microsoft.com/Forums/windows/en-US/8b57df52-e4b5-4b93-b1f2-5b787f0dbeed/windows-7-chainloaderbootmgr-error-13-invalid-or-unsupported-executable-format?forum=w7itproinstall

You may run startup repair using the Windows 7 disc. The Automatic repair can detect and fix the issues that prevent the computer from starting normally. Try the following steps.

1. Insert the Windows 7 DVD or repair disk and restart your computer. Boot from the DVD, press a key if prompted.

2. Choose your language and click Next.

3. Click Repair Your Computer and then select the operating system you want to repair.

4. Click on the Startup Repair link from list of recovery tools in System Recovery Options.

Let us know the results. And reply with all the answers, so that we can research on the issue and help you with a proper response.

Thank You