Common causes are:
1. The PSU was not upgraded to handle this new load. In short (pun intended) you want an ample PSU with a single +12V rail. This is widely discussed so to get this one out of the way you supply the forum with the make, model or the PSU or better yet a link to it's maker's web page.
2. Sometimes it's just drivers. I use https://www.guru3d.com/files-details/display-driver-uninstaller-download.html (DDU.) This is well discussed on what is and how to use so I pause here.
There could be other factors like an out of date BIOS which in the case of cards that REQUIRE UEFI BIOS COMPLIANCE that after we work the other areas we look at this and more with a Web SPECCY report. You can share that report using this link: https://www.piriform.com/docs/speccy/using-speccy/publishing-a-speccy-profile-to-the-web
Hello, recently I purchased a rtx 2060 nvidia gpu for my desktop. Ever since then when I attempt to play games such as Modern Warfare, my pc crashes to black screen and restarts upon loading into a multiplayer Lobby. I'm happy to provide any information needed to help solve this issue. Please let me know how I can help you.

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