Timed strange computer malfunctions?

[AveryMaurice]

This is a problem that has been driving me insane, I think I fix it and then it happens again. My PC occasionally will malfunction and all my applications would participate in weird behavior until restarted, this includes Chrome not wanting to display web pages, Skype logging itself off and whenever I press Ctrl + Alt + Del during these times my computer displays a black screen and completely locks up. Every time it happens, I notice a new application starts to do something weird. I scanned with AVG and House Call with no luck for viruses, I also used CCleaner, this is a really annoying issue and all your ideas are much appreciated.

Avery

[ArmouredBlood]

Basic advice I can give, start in safe mode, obtain your antivirus' newest version, disconnect from the internet, uninstall then reinstall your antivirus, and scan again. I'm sure others will suggest good spyware/malware scanners - I can't really recommend any since I've never dealt with a virus before. I use avast home version, between being careful with sites I don't know and the program I haven't suffered anything beyond a few popups (should get around to looking for the opera adblocker ...).

[pavera]

Did you try Malwarebytes?

When weird stuff like that starts, I usually just give up and reformat.

[GreyGhost]

ArmouredBlood said:

Basic advice I can give, start in safe mode, obtain your antivirus' newest version, disconnect from the internet, uninstall then reinstall your antivirus, and scan again.

While running in safe mode will prevent a lot of malware from starting up that strategy will fail if core executables are infected, in that situation some malware will defend itself by blocking or neutering the antivirus as it's being re-installed. A better solution is to run a virus scanner without starting Windows, which usually means booting a Linux-based live CD. While there's several to choose from if you know where to look, you might like to start with the Kaspersky Rescue Disk which is highly regarded.

[david_a]

You could try testing your RAM. It may be a hardware problem.

If it's a malware issue, don't bother trying to clean it - just reinstall the OS. Once a system has been compromised I wouldn't trust it again.

[Bucket]

I second checking your RAM.
More than once in the past, weird behavior that I'd attribute to viruses ended up being the fault of RAM. Programs would try to take up certain damaged memory addresses, resulting in crashes or other strangeness. This is often the case if your problem is triggered by a seemingly inconsequential action - like the time my computer would completely freeze whenever I tried to resize a window.

[Maes]

Bucket said:

I second checking your RAM.
More than once in the past, weird behavior that I'd attribute to viruses ended up being the fault of RAM.

That, or faulty motherboard capacitors, if you have a mobo made between 2000-2006 (that particular problem should've been solved by now, but bad batches occasionally still find their way into consumer electronics).

Their usual symptoms are random crashes, lockups and BSODs, just like defective RAM. However AveryMaurice's problem sounds more like a software/network problem.

[AveryMaurice]

Yeah, I got my PC in 2009 so I don't think it would be the mobo... I uninstalled AVG and switched to Avast, scanned with no luck still. Malware Bytes showed nothing as well. I'll try checking the RAM, thanks for the information.

[GreyGhost]

I recommend the Windows Memory Diagnostic and suggest leaving the computer on overnight to run the extended tests.

[Creaphis]

Yup, the last time I had screwy issues like that, my RAM was to blame. The funny thing, though, is that my RAM failed immediately after a friend of mine had been loading warez onto my computer, so I was certain that a virus was to blame. I ended up formatting everything, and I only got clued into the real problem when Windows wouldn't reinstall without my computer crashing.

[Aliotroph?]

Yeah, memory sounds like the culprit here. Having either bad memory or bad data in memory can do really weird things. The amusing part is how consistent it can be. If you are writing a program and don't remember to initialize the state of some memory you are reading you can get surprisingly consistent, but still completely insane and nonsensical bugs.

The last time I had a weird crashing issue I went from thinking it was software to thinking it was RAM. Well, it wasn't the RAM. I noticed one day the computer didn't crash when the room was hot. I started keeping it warm and it never crashed. When it did crash the BSOD code (only visible in Vista) was 0x101, which is about a secondary processor not receiving a clock interrupt signal in the allotted time. We decided there's a bad electrical connection (quite possibly just a bad solder point) somewhere in there and it opens up when the room is cold. Funny thing is that machine never crashes if we run Linux on it.

[RestlessRodent]

Aliotroph? said:

Yeah, memory sounds like the culprit here. Having either bad memory or bad data in memory can do really weird things. The amusing part is how consistent it can be. If you are writing a program and don't remember to initialize the state of some memory you are reading you can get surprisingly consistent, but still completely insane and nonsensical bugs.

The last time I had a weird crashing issue I went from thinking it was software to thinking it was RAM. Well, it wasn't the RAM. I noticed one day the computer didn't crash when the room was hot. I started keeping it warm and it never crashed. When it did crash the BSOD code (only visible in Vista) was 0x101, which is about a secondary processor not receiving a clock interrupt signal in the allotted time. We decided there's a bad electrical connection (quite possibly just a bad solder point) somewhere in there and it opens up when the room is cold. Funny thing is that machine never crashes if we run Linux on it.

Are you running a legally licensed version of Windows? heh

[AveryMaurice]

GreyGhost said:

I recommend the Windows Memory Diagnostic and suggest leaving the computer on overnight to run the extended tests.

Ok, thanks, I'll give it a shot. If the RAM is failing must it be replaced or is their a software-related way to resolve the issue?

[Aliotroph?]

GhostlyDeath said:

Are you running a legally licensed version of Windows? heh

Yes. When we ran Windows on that machine it was always an MSDN copy I got from Dell when I worked there. I don't see how that would make a difference anyway. A cracked copy of Windows doesn't know the difference except there are usually one or two WGA updates left out. A machine with activation issues is a very different beast.

That strange hardware issue gave that BSOD on Vista. On XP the machine would just lock up. Seems to work better on Linux.

[GreyGhost]

AveryMaurice said:

If the RAM is failing must it be replaced or is their a software-related way to resolve the issue?

I wish there was a software fix. The usual fix is replacing the RAM but before doing so it'd be worthwhile improving the airflow around the modules to see if the problem's heat-related.

[Maes]

AveryMaurice said:

If the RAM is failing must it be replaced or is their a software-related way to resolve the issue?

There is a temporary workaround if your computer has a video card with shared memory, and the fault is localized in the upper memory regions (where the video card normally reserves its shared memory from): if the damaged area falls into the video region ONLY, then you can get away with it and at most you'll see a visual glitch now and then.

I had an old laptop that had 128 MB of RAM, of which the upper 16 were reserved for the video card. What's more, that first module was soldered (!) to the mobo, and couldn't be replaced.

As soon as I inserted a second one to upgrade it, Windows crashed sooner or later. Memtest revealed not long after that there was indeed a bad area near the 112'th MB of RAM (which was within the first, fixed module). As long as that was used for video only, it didn't matter. As soon as executable code started being loaded there...trouble. This meant of course that memory couldn't be upgraded, since it would expose the otherwise invisible fault.

Another similar workaround is to remove ONLY the defective module, is there is a damage localized cleanly within one and you can live with less RAM.