Windows 7: Windows 7 - 64 bit - WDFLDR.SYS missing or corrupt

I hope im in the right section, if not: please accept my apologies

I'm experiencing a pretty bad problem with Windows 7.

I'm unable to start Windows (neither normal nor safe mode).

What i have done so far to try and fix the problem:
- Run System Repair (3 times), 1st run it found errors (cant fix), 2nd run it found errors (cant fix), 3rd run it told me everything was fixed.
- Rebooted, still the same problem.
- Ran chkdsk /f /r from command line, ran for like 5 hours but nothing was found
- Ran the memory check (from recovery tools), everything oke.
- Ran System Repair (3 times), same outcome as first.

The error im getting is:

File: WDFLDR.SYS
Windows has failed to start because a required system file is corrupted, or missing.


I have been searching google (and this site, and like 50 different sites) but nothing really seems to work, and most issues reported with this file concern Windows Vista...

Anybody has any idea what I can do to try and fix this?

PS: i cannot add an error dump because i cant get to my desktop

Hello Verduveltje and welcome to Seven Forums. Sorry to hear you're having these issues. I think the first thing I'd try is to run the Microsoft Standalone System Sweeper tool and check for malware. According to Webroot the wdfldr.sys file can show the following behaviors:

• Uses rootkit techniques to conceal its presence, interrogation or removal
• Uses low level functions to hide itself from the user and from system/security processes
• Found on infected systems and resists interrogation by security products

WDFLDR.SYS, Prevx

The Standalone System Sweeper has has pretty good results finding and eliminating these kinds of problems.

http://www.sevenforums.com/tutorials...m-sweeper.html

It would also help us if you'd show your system specs and give us a bit more info about how your Windows 7 was installed. Was it factory installed or did you upgrade from a previous OS? If factory installed does your machine have a hidden factory recovery partition? You indicated you ran chkdsk from the command line. Have you tried running the System File Checker scan from an elevated command prompt?

SFC /SCANNOW Command - System File Checker

Hi Marsmimar, thanks!

I am currently not at home, so I cannot access the laptop but running the "Microsoft Standalone System Sweeper" will be the first thing il do when i come home, il also run the "SFC /SCANNOW Command"

Some background information:
The system was functioning just fine last sunday, than i started it yesterday and i got the error. The laptop is an Acer Asprire 5470g with the following specs:

CPU: Intel Core i5 430M 2,26GHz
BIOS Chipset:Intel Mobile HM55
RAM: 4GB - DDR3
VIDEO: Radeon Mobility HD5470

It did not come pre installed with windows 7 i believe (im not sure though). I did get into the preinstalled hidden recovery partition (system repair and stuff without a cd), but i cant find that anymore... ive been staring dead at my screen and just cant remember how i got there, so i have created a recovery disk to run the system repair the 2nd time.

Btw, do you think this problem can be fixed without me loosing my data? I sure hope so... I swear to god from now on i will make system recovery points frequently :S i thought I made one but I never did...

I will get back to you with the results of those two things asap.

First, I have to offer my usual disclaimer: I'm not an expert at anything.

To answer your last comment first, system restore points have limited use. They contain information about registry settings and other system information that Windows uses. It doesn't do anything to save personal files or data. For that you should regularly back up your personal files and important data using a backup program.

Sources:
What is System Restore?
System Restore: frequently asked questions
What to do if Windows won't start correctly

My personal suggestion is to rely on System Images. A system image is like a snapshot of your entire hard drive and is best stored on an external hard drive. If a machine crashes you can restore that image in about 30 minutes or less and your machine will be in the exact same condition it was in at the time the image was made. All data, all programs, all personal settings, all updates, etc will be there. The newer the system image the better shape your machine will be in. External hard drive prices have come way down. I think I read they're running about 10-12 cents a gigabyte. (500GB = $50-$60 or so, 1TB = $100, etc.)

Can you recover your computer without losing data? Maybe. Depends on what's wrong with it. If you can eventually boot into Windows you might be able to do a Repair Install which preserves user data, files, drivers, etc. There are several warnings to heed but don't get ahead of yourself. If you have a hidden recovery partition or if it becomes neccessary to do a clean install, you will lose everything. The hidden recovery partition would return your machine to factory specs while a clean install will erase everything on the hard drive and give you just the operating system when finished. Let's see what the System Sweeper results are and go from there. BTW, I work at night so if I don't respond immediately...

Alright so i did the "Microsoft Standalone System Sweeper" and it found 3 threats (had to do with java), they were fixed and i tried rebooting, same problem.

than i did the "SFC /SCANNOW Command - System File Checker" and it gave back this:
"Windows Resource Protection did not find any interity violations"

tried rebooting again, still doesnt work, it goes to system repair even without the recovery cd inserted.

In the diagnosis and repair details i found the following errors:
Numer of root causes: 2
Boot critical file: C:\Windows\system32\drivers\Wdf01000.sys is corrupt.
Boot critical file: C:\WDFLDR.SYS is corrupt.

edit:
i just read somewhere els that the SFC /SCANNOW command (can) take really long, it took like 1 minute to run though... dont know if thats a good or a bad thing?

Also found the following: Link. Might that be a solution for both .SYS files?

edit 2:
Just rebooted and the system repair again, gives no errors now and:
Boot status indicates that the OS booted succesfully

So i rebooted again, and it gives the "Boot critical file: C:\WDFLDR.SYS is corrupt." error again (keeps going to system repair automatically)

It ran system repair again and now gives the following:
"Startup repair has tries several times but still cannot determine the cause of the problem."

rebooted again, again gives this: "Startup repair has tries several times but still cannot determine the cause of the problem."

Tried to boot in safe mode, goes straight to system repair again and again gives this error:
"Startup repair has tries several times but still cannot determine the cause of the problem."

Went to system repair myself and ran the SFC /SCANNOW command again but it tells me "There is a system repair pending whigh requires reboot to complete. Restart windows and run sfc again", restarted my laptop, tried again and i keep getting the same message.

Im out of options for now, how you can help me and hope any of what i posted is usefull!

Minor update:
i have ran a chkdshk /f /r last night and it came up with no errors except for the fact that it cant write away the log file.


Anybody has a clue on what to do next?

What i do remember is that i have "installed" a new driver the last time it ran properly as in i have inserted a usb device which installed a driver itself (it should), might it have something to do with that?

Under the circumstances I think I'd try a Repair Install unless one of our more knowledgeable forum members has a better suggestion. You'll need to find a retail (not OEM) installation media with the exact version of Windows 7 now on your machine. That means the install media must also be the correct "bitness"; either 32-bit or 64-bit to match what's on your machine. You can borrow the install media from a friend or perhaps find a site on the internet for official Windows 7 ISO downloads. (Forum rules prevent me from giving a direct link.)

Repair Install