windows 7 failed to load because a critical system driver is missing or corrupt

If you boot from the disk you are offered  repair, that only means a startup repair, etc., not an repair install upgrade.

You can't repair upgrade install 7 from a non-bootable system.

7 has to be up and running to do that.

This is what you will be offered: Do a system restore or a startup repair

https://www.sevenforums.com/tutorials/139576-startup-repair-infinite-loop-recovery.html

If one performs a Google search and read results about this problem and solutions that actually work and wisely ignoring the ideas that begin with the word "try" - the solution seems to be to just replace the missing/suspicious file with a known good copy.

It would be interesting to know what you think happened prior to this incident - if the system was working proerly what do you think happened to it since the last time it did work properly.

From your Windows 7 installation CD you could perform System Restore which might work, from a Command Prompt you could run the System File Checker (SFC) which might work or if you tell us the Windows 7 Edition (Home, Pro, etc.) and architecture (32 or 64-bit) I can put a copy of the file you need on my OneDrive, you can download it to a USB thumb drive and see about copying it on the afflicted system.

Some successful results involve booting on some other media like a Hiren's boot CD and then replacing the missing/suspicious file.

I guess we'll have to see what happens next.

If one performs a Google search and read results about this problem and solutions that actually work and wisely ignoring the ideas that begin with the word "try" - the solution seems to be to just replace the missing/suspicious file with a known good copy.

It would be interesting to know what you think happened prior to this incident - if the system was working proerly what do you think happened to it since the last time it did work properly.

From your Windows 7 installation CD you could perform System Restore which might work, from a Command Prompt you could run the System File Checker (SFC) which might work or if you tell us the Windows 7 Edition (Home, Pro, etc.) and architecture (32 or 64-bit) I can put a copy of the file you need on my OneDrive, you can download it to a USB thumb drive and see about copying it on the afflicted system.

Some successful results involve booting on some other media like a Hiren's boot CD and then replacing the missing/suspicious file.

I guess we'll have to see what happens next.

A warning for you:

I don't think you should try that at all.

You should start by booting on your Windows 7 media as suggested, then use System Restore, Startup Repair as suggested first - those are the easiest things.

Follow the instructions in this provided link:

https://www.sevenforums.com/tutorials/139576-startup-repair-infinite-loop-recovery.html

That will allow you to perform a System Restore and a Startup Repair - the easiest things to do.

Following all the instructions in your given link i face obstacles at step 13(ii). The default,sam,security,software and system files are 0 bytes.. as their instruction i should stop doing that.. they said to find another way. WHAT IS THE WAY??

What happened in the attempts for System Restore and Startup Repair?

If you have a missing/corrupted file Step 13 is not what you need to be doing.

If the files are zero bytes then you have some other problems which I have no idea how to fix.

Since the article is from the SevenForums community you could begin a new topic out there and see if they can help.

https://www.sevenforums.com/general-discussion/