Recently got a new computer built. It was working great. But I wanted to upgrade to win 11 while using my old SSD. After converting the SSD to GPT (GUID) instead of MBR partitioning, I ran into the following issues.

1. After sleep or shut down the computer would no longer be able to boot.

2. Finagling with CSM, Legacy vs UEFI, did not work.

3. Disabling Fastboot made this a nightmare because it's difficult to force the BIOS. (Actually, just need to hold down F2 when you power it up until you see the BIOS but you do stare at a black screen for a while) (and make sure your HDMI or DVI cable plugged into the graphics card instead of the motherboard.)

4. 'fixing' the issue using win 10 troubleshooting did not work.

Eventually after many shenanigans, I would end up with the Republic of Gaming BIOS giving me a specific CPU Fan Error. Well, I had liquid cooling so yeah of course there's an error. There's no fan to monitor. The error message encouraged me to disable the CPU fan monitoring in the Bios. However, when I first had it before attempting to convert my SSD from MBR to GPT/GUID, it was working fine w/ this error. So I hadn't paid it any heed, but it was actually my problem. After installing WIndows 11, Win 11 just would not boot. Without Fast Boot, it would just go to the error message than the BIOS. With Fast boot you just get a black screen and you cry, because unless you know your monitors, cables, SSD, everything is working fine you have a lot to troubleshoot through.

Solution: Force boot into BIOS, disable fastboot just in case. GO to Monitor --> CPU configuration --> Set the CPU Fan Speed to IGNORE. Then Windows 11 will actually start. Without fastbook it may take a minute, but it worked and now i'm not crying. I write this post so that people may find it in their google searches.

My relevant swag:

ROG STRIX Z590-E GAMING WIFI Motherboard

Intel i9 11900k

NVIDIA 3090 graphics card

Windows 11 from USB

Liquid Cooling System.