MSE keeps turning off while using the computer

I have a Windows 7 x64 installation at work, and for some reason MSE keeps turning off, and I get a little popup telling me it is deactivated, and that I should turn it on. It happens most when I'm using my browser (Firefox), but I only visit specific websites that I have been using for years for work related functions.

Turning on MSE takes forever. I've run scans with both MSE and MalwareBytes and turned up nothing. I'm not certain what to look for in the event viewer, or in any of the logs to see why this is happening.

Does anyone have a suggestion as to how I could troubleshoot this problem?

Thanks.

Work Machine Specs:

Phenom II 965 BE
ASUS M4A79XTD EVO motherboard
1 x WD 500 GB drive
Sapphire Radeon HD6450 vid card
Logitech KB and mouse
Generic 450W PSU

Does your work use another corporate anti-virus product by any chance?

If you upload the eventviewer log, I'll have a look if you like.

Is the machine connected to a network?

Golden said:

Does your work use another corporate anti-virus product by any chance?

If you upload the eventviewer log, I'll have a look if you like.

No we use hardware firewalls. Users are responsible for the AV on their own machines. I'll upload the logs in the morning. Thanks.

Boozad said:

Is the machine connected to a network?

Yes, we have a corporate network comprised of Windows and Linux machines, as well as Macs and network enabled communications gear. This just started happening within the last couple of weeks, so something must have changed recently. I'd ask IT, but I'm not sure what change would be relevant to ask about.

@ Golden

Here are the log files:

Event Files.zip

Thanks for looking into this.

I'm unsure whether this is the issue, but I've see a few of these:

Code:

Error	20/04/2015 2:23:24 AM	Service Control Manager	7031	None	The Microsoft Antimalware Service service terminated unexpectedly.  It has done this 1 time(s).  The following corrective action will be taken in 100 milliseconds: Restart the service.

Information	20/04/2015 2:23:24 AM	Service Control Manager	7036	None	The WinHTTP Web Proxy Auto-Discovery Service service entered the running state.

Error	20/04/2015 2:23:23 AM	Microsoft Antimalware	5008	None	"Microsoft Antimalware engine has been terminated due to an unexpected error.
 	Failure Type: Hang
 	Exception code: 
 	Resource: file:C:\Downloads\GenuineCheck.exe"

It appears that when the Web Proxy Auto Discovery enters the running state, then the MSE service terminates, then restarts again. So, I'd say it appears to be network-related? There are a few that are similar to suggest a network-related pattern....but I don't know enough to say one way or the other. Perhaps Gav has more suggestions.

Check the file shown in red - MSE hung on that file ... I don't think its related, but may be worth checking out further.

I've been asking at work about this to see if I could get any help, we have a large network with maybe nearly 3,000 PCs hooked up, and I have one where Symantec just will not run. I've tried several times to sort it out but it will not have it and I don't have the administrative privileges to work at a higher level on it. I think this could be down to the company's network settings rather than MSE or the hardware itself. It's definitely something for IT to look into.

Thanks for the advice guys. I'll definitely have IT look into it.

I appreciate the help.

Well, the IT department fixed it. They forced me to use McAffee. Yippee.

Ugh. Sorry mate.