Fix: Dell Laptop Won’t Boot – Blue Screen of Death and Error 7B

Fix: Dell Laptop Won’t Boot – Blue Screen of Death and Error 00000000007B

This is a serious error.

It doesn’t seem to damage any data, but it can certainly stop you from using your windows computer for days or weeks until it is solved. It took me days and I’m (in theory) a computer whiz.

You can reasonably worry that you have lost all your valuable data. I had this 7B error happen to me twice in a year of using twin Dell Laptops, for two different reasons.

Even after you solve this, you’ll never get back the business harm and emotional harm it causes.

A bigger threat from this problem is it is non-trivial to diagnose; and someone, whether novice or expert, could accidentally do harm to the file system while trying to fix it with standard tools. And neither Dell or MicroSquish help much.

Symptoms and Diagnosis:
Windows won’t boot.

Flashes the Blue Screen of Death and restarts – over and over again.

Eventually you get an option to run Windows “Launch Startup Repair” process – whatever that does. Nope. Startup Repair has never fixed anything for me.

Repair Registry – nope.
System Recover – no joy.

Solving this the first time required reverting an obscure BIOS change – that I did not make (Dell BIOSes get modified without you – far more than healthy. Some badly behaved program or undocumented keypress keeps turning my brightness control off.) This fix and diagnosis is not documented anywhere on the web; nor is it discussed on any forums. I wonder if it is caused by a weak motherboard battery.

The second time it was cured by booting with “Last Known Good Configuration.”


First solution:
Dell’s Latitude BIOS has a setting for SATA type: ATA, AHCI and RAID. Somehow that got switched on my Latitude BIOS e6440 to “ATA” without me knowing it. And BSOD.


One appalling facet of this mess is that MicroSquish’s BSOD error only flashes on the screen before rebooting. Way too fast to read the error; let alone transcribe the 20 digit hex numbers.

So I first tried taking a photograph of the BSOD.

Nope – I made more than 70 still pictures of the screen as it popped up, but it flashed by too fast. What worked was taking a video and playing it back on frame at a time. That’s when I could see the error was “00000000007B” – not 7e or 78.

This BIOS error is not documented anywhere in Dell’s manuals or on any Dell web forums that I could find. I must have tried 11 or 12 different ways to recover from this.

Tom’s Hardware has a lot of good tips for other boot failures – in plain English.,10036.html

Microsquish makes solving everything painful
(No it’s not an accident. It’s a culture of arrogance sown and grown by Mr. Gates)

“Windows Boot ‘Genius’ ” failed miserably.
It couldn’t even make a valid bootable USB. “Genius” is a totally bogus term for that program.

Sadly none of them worked.

Solving it was a fluke.
After the other methods failed, I started checking each BIOS setting with a twin laptop that was working to find any setting that caused the error.

I eventually found the SATA hard drive type was subtly changed to ATA instead of AHCI. After setting it back to ACHI – all was fine ! It resumed booting normally !

Thank goodness there were apparently no ill effects from having a windows system trying to boot with the wrong SATA setting. It turns out Dell allows BIOS modifications from windows. And apparently some ill-behaved program (or undocumented keystroke) decided to change my SATA type in the BIOS. Or possibly it might be a failing battery that reverts the BIOS setting to a deafult.

The stupid thing is that even a dumb BIOS should be able to detect which SATA type the drive is on bootup – and ask if you want to override a wrong setting.

Second failure and solution:
Boot into “Last Known Good Configuration.” (LKGC)
Thank goodness that worked !

Why did LKGC work – but Windows “Launch Startup Repair” didn’t even try to do a LKGC ? Thank MicroSquish for this stupid oversight.

And some wonder why I complain about the enormous, expensive incompetence in the computer and software industries …

Not convinced? Ask yourself why with Terrabytes of disk memory (enough to store tens of thousands of books) going for under $100 (meaning there is no disk space limit), WHY is there no FULL offline help for every part of your darn confuser system that has sold more than a million copies?

My opinion – Simple pompous arrogance – related (but not identical to) to “Illusory Superiority” or technically the Dunning-Kruger Effect. Its more accurately the “We’re smarter than you and want to keep you ignorant, so you need us” principle.
See —–Kruger_effect

Postscript: Mainly due to this bad design avalanche that lost me a load of work time (how much money would you lose when locked out of a computer you depend upon for weeks), no diagnosis documentation (Dell’s failure), and lack of onboard error catching and repair (Dell’s Bios design failure)- I’ve switched to another brand. Goodbye Dell.

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