Windows update messed up system, cannot boot. How to fix bootloader?

Hi all,

Doing this for a friend. I did the initial install a month or so ago and it's been great. A day or so ago, he reports that Windows did an update overnight and ever since, it's stuck in the system repair boot loop.

As well as this boot issue, system restore did show restore points and even let me check affected programs, but when I chose to proceed, it said to turn on system protection?

After running sfc/chkdsk (no issues found), I thought to double-check things w/diskpart. Following Chris Titus' video, I set the proper drive letters to the Windows system drive and to System reserved. I then ran the following:

bootsect.exe /nt60 all /force (boot code successfully updated). Next was:
bcdboot c:\Windows /s G: /f ALL (G is system reserved).

However, instead of seeing, "boot files successfully created", I get:

"failure when attempting to copy boot files" (when copying to the 50mb system reserved).

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Having a few more minutes seeking info online, I came upon directions stating the location "C:\Boot" when using bcdedit to export BCD, which was successful. Then, attrib c:\boot\bcd -h -r -s failed as this system shows the folder "Boot" within C:\Windows....

I need a guru! Anyone here who knows how to help me fix this & lead me back to the desktop? I'm hopeful it's only a bootloader issue as chkdsk/sfc came back okay.

I believe this was Win 10/2004? Possibly 20H1, but more likely 2004.

I'm going to say MBR and likely not UEFI (older Toshiba laptop). How to confirm if it doesn't boot?

*11pm here, and off to bed. I can follow directions if there are particulars you need me to get. I can boot to external USB Win 10/cmd.

You must check if the main drive is UEFI-GPT or Legacy-MBR
Boot from Win 10 installation drive, and launch a CMD Window (Shift+F10). Type
Diskpart
list disk (on the last column see if the drive has an * on GPT )
exit

Megahertz said:

You must check if the main drive is UEFI-GPT or Legacy-MBR
Boot from Win 10 installation drive, and launch a CMD Window (Shift+F10). Type
Diskpart
list disk (on the last column see if the drive has an * on GPT )
exit

Yep! Good starting point! Won't let me give you a rep

If you open the log file, you’ll be shown details of all the tests performed by Startup Repair, with any errors discovered detailed. We can use this information to help diagnose and get to the root cause of the problem.



To open log file from the Windows Recovery Environment, click and open the Command Prompt. When the Command Prompt is open, type Notepad and press Enter key to open the Notepad application. The Startup Repair log file is located at:

Code:

C:\Windows\System32\Logfiles\Srt\SrtTrail.txt

You will need to navigate to the drive on which you have Windows installed (usually the C: drive) to see the SrtTrail.txt log file.

Megahertz: no, not GPT.

FreeBooter: log attached, but doesn't look very helpful.

I run Linux Mint as my everyday. I can copy out the entire SRT folder if that would help? It's only 4mb total.

Boot critical file f:\windows\system32\drivers\klelam.sys is corrupt.

klelam.sys is part of Kaspersky™ Anti-Virus

Rename the klelam.sys as klelam.sys.bak and reboot your computer.

What is the command to do this? I'm not familiar and I have just searched and there's nothing specific (which I find odd). I see lots of other "answers" about bulk rename, folders, iso's, etc, just not that.

I will be booting to a USB Win 10/2004.

Thank you

I'm guessing: rename drive>folder>filename.sys drive>folder>filename.sys.bak

but I know things are different when booted to recovery/installation media.

Open Command Prompt from Recovery Environment and execute Notepad.exe and from Notepad click File --> Save --> Save as type: dropdown box choose file type All files (*.*) this will allow to see all file types.

Navigate to C:\windows\system32\drivers and rename the klelam.sys to klelam.sys.bak