Need Some Thoughts on a Problem My Son is having

idea dont do anything major with the computer. just browse the web for a couple days and let it update does it still have issues.. if no its something he is doing....

Could be something as simple as malware bytes or an antivirus.
@wwillson beat me to it.
If it happens again pull up task manager and see what it’s trying to do. I had a problem on my Asus (before I installed a NVMe SSD) where windows 10 would just sit there and hammer the (older spinning) hard drive for no apparent reason.
I need some toughts from folks who know computers. A few weeks ago, my son paid over $2000 for a very high end MSI computer. While he has a day job, he also is an artist and loves playing games. He wanted more speed, memory, etc. Well, he gets it home, sets it up (he is computer literate), gets it running and begins to download some Microsoft apps from the Microsoft "store". All goes well for about 72 hours and suddenly stuff like the search function stop working. This continues to get worse. He takes it back to Best Buy and the Geek squad does some stuff. Works again but at around three days, same stuff starts to go bad. They give him another computer. Same thing. Takes it back, gets the third computer and behold, the same thing happens at around 72 hours. He calls Microsoft and they look at it over the phone, do some software manipulation but cannot correct it. They tell him they have no idea. He calls MSI and they basically hang up on him! So he is taking it back to Best But for a fourth computer. Nobody seems to have any idea. He deletes all the apps he put on but the problems remain. He has taken the computer back to ground zero, restarts it and the problems remain.

1. Bad set of ROM or RAM chips?

2. Hidden virus that has a 72 hour timer built in?

3. Some software glitch that has not been identified?

4. The witch of December came calling....

Any ideas I can share with my son would be appreciated!! Thanks in advance.
I cringe at the thought of taking something back 3 or 4 times and getting a replacement. If the second one didn't fix the issue, why would the third or fourth? That just raises prices for everybody.

I'm pretty sure hardware has been ruled out by now, which leaves two things: software and user. The fact that you say it happens > 72 hours make me wonder if it's something he's installing. Or it could be Windows updates (though in my experience Windows updates on the newest versions of Win10/11 have been very reliable.)

He needs to take a methodical troubleshooting approach. Use the computer as-is for the first 72 hours. Let the updates install and do their thing. If all is well, install the apps/software one by one, testing between each app install. If one installed app breaks it, you have your answer. If it breaks before installing apps (presumably during/after Windows updates) you have the only other possible (in my opinion) answer.

You have to assume that model of laptop is selling in the many thousands. They can't all have issues or they wouldn't be for sale, so I think it's unlikely it's a hardware or Windows issue.
Probably running more than one security suite.
The first thing you do with any computer is to delete the bloat ware that comes with it. In other words any free trial BS.
Norton or McAfee get rid of it. Use the included Windows Defender only.
This is what I found out when I try to install Office 2007 in my dad's pre-build HP with Windows 10. Apparently HP installed a copy of the newer Office and would only activate it if you buy a license, yet all the registers stuff is screwed up with it, that even if you uninstall it, reinstalling office 2007 will still not work right. I ended up spending a lot of time finding out what register hack I need to run to get it to use office 2007 on it without having to go with a clean install.

So, for your sun I suspect some bloatware MSI did (just like HP, Dell, and everyone else) that prevents your son from installing old stuff on it, maybe they didn't test backward compatibility.

If I were your son I would just do a clean install of Windows 10 (not windows 11), and see if it works. I do not think this is a hardware problem but rather some software compatibility between drivers, applications, OS, and the pre-build's bloatware.
All security suites were removed except for malWare bites. Conversations with Microsoft last evening....their advice was to return the computer and get yet another one!!!
In the search box on the taskbar, type in Winver and post a screen shot. If it is a Windows "S" version it will be the minimal that uses only MS store apps.
It can be upgraded to the full version free.
Highly unlikely a high dollar gaming laptop comes with a neutered version of Windows that can only run store apps.

I would suggest returning for a refund and trying a different brand/model at this point, if he's not adept at wiping the thing clean and reinstalling a fresh copy of Windows.