Exporting video crashes my entire computer

Hey all,

I've been searching around the forums trying to solve this problem myself for the past few days, but everything I've tried has failed... so I figured it's time to reach out.

Every time I attempt to export the latest project I've been working on (a 25-ish minute video), I get a few minutes into the export process before my entire computer crashes and reboots itself without warning. I've made videos in the past, always on much weaker computers, and never had this problem... but it's been months since the last time I made one so I can't say exactly when the issue began. Whenever I try to export a video, my cpu usage shoots up to 100%, and a few minutes into the estimated 35-40-ish minute render time it gives up and expires.

Some of my specs:

Windows 11 (too late to roll back)

Processor: 11th Gen Intel(R) Core(TM) i5-11400F @ 2.60GHz

Video card: NVIDIA GeForce RTX 2060

RAM: 16 gig

Premiere pro (version 23.0) is installed on my SSD but is writing to my regular drive - which is also where half of the raw footage is located, the other half is on the SSD. Both drives have well over 150gig of free space.

Things I've tried:

• Switched to software-only rendering and rendered all of the videos on my timeline
• Updated my GPU drivers
• Updated Premiere Pro (I freshly installed it just before starting this video)
• Exporting as high quality 1080HD instead of 'match source - adaptive high bitrate'

I don't know much about video or video editing so I have no idea if I'm doing anything wrong... I had mistakenly recorded about half of my footage in mkv and used external software to convert the files to mov so I could bring them into Premiere Pro - in case that affects anything. 

Thanks in advance!

Dins