Computer keeps freezing - how do I find problem

Viruses and worms
1

Hello,

My PC is occasionally freezing with no apparent activity (no hard drive activity). Under normal use its only an occasional thing and a reboot by switching the power off and on again is the only way to recover.

I can get it to freeze by running scans. Windows Defender freezes it about half-way through its scan. Microsofts malicious software removal tool in the monthly updates also did it. I’m using the Avast Free edition (program version 6.0.1203, virus definitions version 110810-1) and a quick scan with that ran successfully but a full system scan freezes the PC around the half way mark.

The PC is running Windows Vista and is up to date with patches. It started a few days ago and the only other possible symptom is that there are normally a few system restore points available but when I tried it there was only 1 available (created after the first freeze when windows update Windows Defender).

Can anyone suggest any thing I can do to find out if I’ve a virus or malware on the PC? Or anything else to try and work out whats wrong?

Thanks,

David

2

Follow this guide from our expert malware remover Essexboy
http://forum.avast.com/index.php?topic=53253.0
( post the logs HERE and not in the guide )

To avoid using multiple post with copy and paste you have to attach the log`s
Lower left corner: Additional Options > Attach ( Malwarebytes log / OTS log ) save OTS log as ANSI

Essexboy will look at the logs when posted…if you hurry you may get him before he goes to bed…so only run a quick scan with MBAM

3

Thanks, ran a quick scan with MBAM and that ran okay and didn’t find anything. Haven’t time to run a full scan tonight but will do so tomorrow. I’ve not heard of OTS before, what is it?

I’m currently running a scan with Spybot S&D as I’ve already got that installed. Hopefully something will work.

4

OTS is a system analysis tool to look in the malware hijack points

Lets have a quick look at your temperatures whilst we are at it

Download Speedfan and install it.

Once it’s installed, run the program and post here the information it shows.
The information I want you to post is the stuff that is circled in the example picture I have attached.
If you are running on a vista machine, please go to where you installed the program and run the program as administrator.

http://artellos.geekstogo.com/speedfan.png
(this is a screenshot from a vista machine)

5

Installed speed fan and get a GPU temp of 63C and HD0 temp of 46C. Thats the only info on there in the area’s you circled.

6
Haven't time to run a full scan tonight but will do so tomorrow.
Not necesarry...

http://forums.malwarebytes.org//index.php?showtopic=10405

7

Interesting that there’s so little difference between the quick and full scans. May run it anyway to be thorough. Spybot just finshed and ran okay. Will try OTS tomorrow, and also SuperAntispyware as I’ve that installed already.

8

compared to Malwarebytes… SpyBot is a toy… not worth disk space :wink:

9

SpyBot is obsolete!
Malwarebytes is very good.

10

63 is a tad high - could you clean all the vents on your system and ensure that there are no blockages

11

They are a bit dusty so will clean them.

I’ve attached the first part of the OTS log. The second part and MBAM to follow.

12

Second part of OTS log, and MBAM log

13

Nothing of import showing there, so I would suspect that it is a temperature problem

Does this occur more often the longer you have the computer turned on ?

14

No, it doesn’t appear a time issue, more what I do triggers it. And its repeatable, that is I can create the problem just by running a scan using windows defender (and a couple of other things). Although it does happen occasionally at other times as well (possibly a background process such as indexing accessing whatevers the problem).

I’ve just tried turning the PC off, cleaned out the vents as best I could then turned it back on. After using it for 20 mins or so the temperature was 59C, does that sound better?

I then tried running windows defender and it froze the PC again at about the same point. The object it said it was scanning on the screen at the time was part of the registry. I’ve run the registry cleaner thats part of CCleaner and that found a couple of errors with unused file extensions but nothing that matched what was on screen when the computer froze (which was a HKCU internet settings object).

Is it possible something in the registry is corrupted? Is there any good registry scanners I could use? Or is there anything else I could try?

15

59 is still high - here are my temps

16

The 59 was the GPU temperature (actually at 57 now). HD0 is at 44.

I’m not sure how it can be a temperature thing though as the same action is triggering the problem no matter how long its been on for.

17

If the temperature is high then as more programmes run they will increase the CPU temperature until either a freeze occurs or windows shuts down

I can see no apparent malware

18

Okay, thanks for all the help. But still not convinced as its happened when I’ve started up the PC and run windows defender straight away.

Will open up the PC tomorrow and see if I can bring the temperature down a bit more to see if it helps.

If it isn’t malware or temperature (a big if) any idea’s what it could be or where I could go for advice/help?

Thanks again for the help.

David

19

The next process would be to go for a clean boot and then check the services one at a time to see if there is a conflicting driver

20

While you have the pc opened, you should also clean all the dust out of it, especially on the heat sinks, not just the vents. Also check that all fans are working, holding a piece of paper in front of them is a quick easy check. It could be a lot of other things as well, but these are easy to do.