Just yesterday I was playing around with my hard drive partitions, trying to delete an old Ubuntu dual-boot. Past Pete was silly and didn't properly label said partitions so current Pete deleted the Windows master boot record.

Basically, I had two operating systems on my computer and while trying to delete one I accidentally deleted the critical instructions Windows needs to turn on and shut down.

Oops.

Not to worry, a quick lucky Google search led to one brief instruction article. It was very clear:

1. Download the Windows 10 64 bit .iso recovery file.
2. Download the Windows Upgrader / Media Maker program.

Assuming at that point the program would simply accept my downloaded .iso file, I let the separate 4.2GB file finish. The tool never asked for my file, but proceeded to get a new copy all on its own.

Here I am 45 minutes of downloading later chuckling to myself, thinking someone might as well learn from my mistakes.

A bootable USB or CD can often save the day, but keep in mind that making it is the easy part. It only takes a few clicks and 15 minutes.

Do it before some huge problem happens in the middle of your 12 page thesis due tomorrow that you didn't save yet, please.

Here's how it works:

Your computer has basic startup instructions, allowing the hardware to power up and start running the operating system. That's when you would enter a password and log in. In Windows this is referred to as the master boot record or MBR. Sometimes it can be corrupted, maybe by malware or being a huge dingus.

#Guilty

Anyway, I think it's easier to use a blank USB versus a CD so we'll do that. Skip downloading the individual .iso file, just install that program and let it make its own copy. Plug in a totally blank 8GB or greater flash drive to install the recovery files. It's super easy.

Pro Tip: Right-click your USB in the file explorer and select "Format" to ensure it's ready.

When the USB is ready, plug it in and restart the computer. Enter your computer's BIOS, usually by pressing F2 or DEL during early startup. Look closely, it should display the key required when you're able to press it.

From here you can change the boot order so your PC first runs from that USB instead of the broken instructions it had on the hard drive. Restart the computer. Leave a comment if you need help with this step!

Next just select your language and specify you're repairing instead of installing a fresh system. First try the auto-repair options. These will generally get you back on track for basic issues.

In my case, I had to enter some terminal commands and reconstruct the whole MBR. Because I deleted it. Like a dingus.

But it wasn't so scary.

Those steps can be found in a great article by Tim Fisher at Lifewire.

Also in my case, after those commands I was still seeing "Bootmgr missing". After some grumbling, I actually ran the auto-repair one more time and it booted right back to my desktop. Presto!

All things considered, this was a pretty painless process. Hopefully I've helped you all.

Leave a comment or seek me out on social media (@pjmulroe) to keep the conversation going!