Personal Computer - Lemon ?

There are countless of IT/tech repair shops that will do software and hardware diagnosis on computers. But if you're asking about a computer with an active warranty, you might want to go through them first to see if a given repair shop is authorized to do so. Because if you choose an authorized repair shop, the place or company which you purchased the computer from? Won't accept the diagnosis and you'll be paying for all the work out of your own pocket.

tsarstepan-

It is new, so—I guess—it must be under warranty. That said, I don't have a copy of the warranty or other paperwork.

I don't know if it is defective. I only know that it is extremely slow at times. I have needed to hold the power button depressed for a duration to force it to power down, and then I power up normally.

Then contact whomever you bought it from. Hopefully, you bought it from a legitimate dealer like the OEM (the manufacturer) or a big box store like Best Buy. That should be enough as they would have it in the system on warranty. I'm assuming by "it is new" that it's less than a couple of months old.

If you bought it from a gray market electronics store because it was cheap? You probably bought a refurbished computer and thus are likely not under warranty. And that's on you for shopping in these ethically questionable trash stores. You get what you pay for.

tsarstepan-

It is new and I bought it directly from the manufacturer (i.e., Dell) on its website.

From an anecdotal experience, I never had any problems when dealing with Dell computer tech support.

Actually this is very simple.
You can bring your computer into repair service stores and let technicians with expertise and experience evaluate and advise you.

Or your newly purchased computer can be brought to the warranty center where you bought it for inspection

Furthermore, you should clearly state your working needs.

Or you can do a preliminary check as follows:

- Check to see if the machine is overheating after a period of running.

- Is the operating system you use too slow?

Along with many other problems

How to handle if it overheats, you just need to clean the CPU fan and replace the CPU thermal paste. If it's slow, check the operating system, junk files, viruses ==> you can rerun the computer's operating system if you encounter this problem.