Computer help forum: Desktop suddenly very slow, hard drive spinning...

Thanks to both of the people who posted answers. There are some good solutions in here. I will try them when I get home tonight, and let you know how they work. I actually do back up my system periodically, not to a hard drive but to the cloud through a software I bought called MyPCBackup. Maybe this has something to do with it? When I first got this program about a year ago, it slowed down the system badly every time it backed me up. I couldn't figure out how to back up just the stuff that has been changed rather than everything on the entire hard drive.

I tend to agree with another poster it sounds like a fairly typical malware intrusion problem BUT the PC backup software could be a part of the picture.

An update: I ran a full scan with my anti-virus software (Kaspersky) and I ran Malwarebytes, both while in safe mode, but neither one found anything. Actually sorry, first I ran Malwarebytes in normal mode and it found one thing that I deleted. Then I ran both in safe mode, they found nothing, and the speed did not improve.

My hard drive is nowhere close to full, and I have very little running at startup. I have a bunch of stuff on the Services tab in MSCONFIG, and I tried to do the clean boot thing but the computer was working so slowly that I wasn't able to get it done. I may need to try it again.

Meanwhile I'm also finding that sometimes when I restart the computer it's not loading up properly. Sometimes I get a message like "Reboot and insert boot media" (something like that), and sometimes it says "Disk Read Error, press CTRL+ALT+DEL". Things I've looked at say this could be a sign that the hard drive is crashing, others say like you folks that this sounds like a virus or malware.

Finally, I ran TDSSKILLER through Kaspersky, to check for the Rootkit malware but it didn't find anything. Currently I'm running a full system scan using Microsoft Malicious Software Removal Tool, and I'm 90 minutes in but it hasn't found anything. So even though all signs seem to point to a virus or malware, it's not looking likely that that's what the problem is.

Based on the above, any further thoughts? As always, thanks to everyone for your guidance.

The stuff I see most often with speed issues.

BUT that Disk Read Error would have me doing the hardware checks. Such as proper cleaning of the PC, the cables all snug, no overtaxed power supplies and no dead fans.

Bob

I will try RKILL. What's very weird is yesterday my wife said the computer seemed to be running fine. I had run the Microsoft Malicious Software Removal Tool overnight, and I actually forgot to ask her if it caught anything. The hard drive appeared to be quieter. Then last night my son was using the computer and it started freezing up again. So first of all does the fact that the condition "comes and goes" help with the diagnosis? Second, I should be able to pinpoint a pretty clear time in the Event Log to see what the problem is, right?

And you knew I would lead with that. Today's HDDs with their SMART system reallocates bad spots according to some rules and a problem like this can vanish just by scanning.

It's like the hunt for dark matter.
Bob

I am assuming that this is a hardwire hook up, modem, router cat5 or 6, correct? If this is a wireless connection then scenario(s) could change. The thought then might be server/bandwidth issues.

This is a hardwire hookup (cable). It is like the hunt for dark matter - imagine going on this hunt without being a computer expert. I'll do the hardware checks and run RKILL and hope I zapped it.

Thanks once again.

Tonight I can't even get to Windows. I either get:

Reboot and select proper boot device or insert boot media in selected boot device

or: A Disk Read Error Occured. Press CTRL+ALT+DEL to restart

I'm taking it to a professional, aren't I???

Was all set to have the hard drive replaced, and suddenly this morning I'm able to get into Windows & it's moving relatively quickly. The hard drive is still making noise as though it is constantly spinning.

I'm confused that the situation seems to come and go so suddenly, without any reason I can figure out. Does this sound like the sign of a virus / malware, so I should keep working on that, or the sign of failing hardware?

HDDs will do that when they are beginning to fail. At least you see an early warning and don't have to lose anything as you know to be ready.
Bob

I agree....if I were in your position, I would back up everything and replace the hard drive.