Tip: How to Fix CRT Emudriver "No Monitor Output" Without Reinstalling Windows

[markran]

I've been a happy GroovyMAME, SwitchRes and CRT Emu Driver user for many years. To be clear, CRT Emudriver works great. Period. Even getting Windows into a state where there's no output to any "real" monitor requires extreme carelessness AND completely ignoring Calamity's multiple warnings in the directions.

However, I was doing a clean install while building an upgraded PC for a new arcade cabinet and started goofing around with reckless abandon. Yep, I'm an idiot who ended up unintentionally doing exactly the ONE thing Calamity tells us never to do. Of course, this shouldn't ever happen... but in the very rare event of such boneheaded stupidity you bork your Windows install - the standard advice is "Reinstall Windows."

As soon as I did it, I knew what I'd done. I was fuming at myself for my willful boneheadedness and as penance thought I'd try to figure out a way to recover without reinstalling Windows. Turns out it's possible but not exactly easy. Maybe this is already known by others but it wasn't known to me so I'm posting it here in case it helps someone else as dumb as me (and you really should be ashamed for not following directions).

I'm not going to detail a step-by-step tutorial because if you're someone who should even be attempting this recovery method, you'll find plenty of instructions online to guide you. Since CRT_Emudriver requires disabling Windows driver signing, the trick is to temporarily re-enable driver signing by attaching the borked boot drive to another PC (not as a boot drive this time) and turning the driver signing flag back on in the boot sector. Fortunately, it's not as hard as it sounds because there are many free, open source BCD editors (like "Visual BCD") which make it as simple as a checkbox.

Now when you boot from that drive the standard Windows display driver process will be back in control allowing you to go back and wisely NOT do what you stupidly shouldn't have done in the first place. At least it worked for me. Your mileage may vary and you definitely shouldn't do this if you don't already know enough to have NOT gotten yourself in this mess (yet, like me, proceeded to do so anyway). This means you'll have to do the "Walk of Shame", admitting to yourself you knew better and still managed to screw yourself over this badly... or you could just reinstall Windows. Your choice :-)

[Zebidee]

Did you try booting into "safe mode"? This should load the default video driver, and from there you can uninstall/reinstall drivers as required before rebooting. I like your idea though too.

[markran]

I forgot to mention that in my case the system was halting at the BIOS config screen for some reason I don't recall. It was one of those refurbed corporate PCs you can get cheap on eBay so I wasn't familiar enough with the BIOS to blind navigate through it. But this BIOS was one of the UEFI-based ones that display in high res by default thus try to use a driver. There's usually a BIOS option to disable that but you have to be able to see the BIOS to find it. Yep, I managed to get myself right into the middle of a worst case scenario!

Definitely not my proudest day. Figuring out the BCD edit hack to restore access at least helped to slightly reduce my embarrassment at being so careless.

Edit to Add: In addition to booting Windows in Safe Mode, another possible alternative is to boot from an external USB drive with a recovery environment or alternate OS on it. However, that's only an option if you already have your BIOS configured to boot first from an external USB if a bootable drive is present. While that's always a good thing to enable, I hadn't done so yet on this new machine.