Frequent blue screen whenever use the desktop for more than 5 hours.

Welcome

What antivirus do you use?

Try booting into Safe mode from Advanced Boot Options and stay there for a while. Like a few hours and tell us if you are getting blue screens there.

While you check how the computer works in safe mode, here are few of my suggestions:

Code:

Start Menu\Programs\Alcohol 52%	Public:Start Menu\Programs\Alcohol 52%	Public
Start Menu\Programs\TuneUp Utilities 2011	Public:Start Menu\Programs\TuneUp Utilities 2011	Public
Start Menu\Programs\TuneUp Utilities 2011\All functions	Public:Start Menu\Programs\TuneUp Utilities 2011\All functions	Public

Alcohol 52%:

Please uninstall Alcohol %. It uses a driver called sptd.sys which is known to cause BSODs in Windows 7. Uninstall the software using Add/Remove Programs. Reboot the system. Once the program is uninstalled, run sptd.sys uninstaller to remove the driver from your system.

As an alternative, many people recommend the use of Total Mounter or Magic ISO

System Optimisers:

These programs are known to cause of BSOD's. The windows 7 operating system does not require these registry cleaning software. They often tune-down rather than tune-up and can wreck the OS beyond repair. Microsoft have improved Windows 7 significantly and it is much better at organising and optimising itself than its predecessors. Check this, this and this thread for evidence.

If you feel the need to use a registry cleaning or optimisation software, most of us recommend the use of CCleaner but make sure you back up the registry before making letting ccleaner delete anything.

Uninstall the tune-up software using the free version of Revo uninstaller in Advanced Mode. (Reboot each time you are asked to)

Remove Kaspersky (it tends to cause BSOD-s) and replace with Microsoft security essentials while we're troubleshooting.

• Removal tool for Kaspersky Lab products
• Microsoft Security Essentials - Microsoft Windows

Update to the latest drivers for your video card:

Code:

0: kd> lmvm atikmdag
start             end                 module name
fffff880`0507f000 fffff880`05b79000   atikmdag T (no symbols)           
    Loaded symbol image file: atikmdag.sys
    Image path: \SystemRoot\system32\DRIVERS\atikmdag.sys
    Image name: atikmdag.sys
    Timestamp:        Fri Apr 06 07:48:25 2012 (4F7E4B69)
    CheckSum:         00AABC48
    ImageSize:        00AFA000
    Translations:     0000.04b0 0000.04e4 0409.04b0 0409.04e4

Click on the Start ► Control Panel ► Programs ► Uninstall a program ► Uninstall everything related to; ATI. Restart the PC. Delete remnants of its drivers/older drivers using Driver Fusion/Sweeper Restart

Get the latest drivers from the link below:

• Download AMD Catalyst Drivers 12.10 Vista 64 - FileHippo.com

Choose custom install and deselect catalyst control center during installation as it can sometimes be a problem and then stress the video card.

Video Card - Stress Test with Furmark

• Video Card - Stress Test with Furmark

Monitor your temps with Speccy during these tests

• Speccy - System Information - Free Download

For monitoring the heat/celsius of the system, use Speccy or HWinfo:

• Speccy - System Information - Free Download
• CPUID - System & hardware benchmark, monitoring, reporting

Run the System File Checker that scans the of all protected Windows 7 system files and replaces incorrect corrupted, changed/modified, or damaged versions with the correct versions if possible:

• SFC /SCANNOW Command - System File Checker

Run Disk Check on your hard disk for file system errors and bad sectors on it:

• Disk Check

Free up the start-up, nothing except the antivirus is usually needed.

• Startup Programs - Change
• Troubleshoot Application Conflicts by Performing a Clean Startup

Let us know the results of above ^/whether your computer feels or is more stable or not.

Then proceed with testing the RAM.
Take memtest. Run for 8 passes and test each stick in a know good slot for an additional 6 passes.

• RAM - Test with Memtest86+
• Guide to using Memtest86+ - Geeks to Go Forums

The goal is to test all the RAM sticks and all the motherboard slots.

Check your motherboard manual to ensure the RAM sticks are in the recommended motherboard slots. Some motherboards have very specific slots required for the number of RAM sticks installed.

If you get errors, stop the test and continue with the next step.

1. Remove all but one stick of RAM from your computer (this will be RAM stick #1), and run Memtest86 again, for 7 passes.
Be sure to note the RAM stick, use a piece of tape with a number, and note the motherboard slot.
If this stick passes the test then go to step #3.

2. If RAM stick #1 has errors, repeat the test with RAM stick #2 in the same motherboard slot.
If RAM stick #2 passes, this indicates that RAM stick #1 may be bad. If you want to be absolutely sure, re-test RAM stick #1 in another known good slot.
If RAM stick #2 has errors, this indicates another possible bad RAM stick, a possible motherboard slot failure or inadequate settings.
3. Test the next stick of RAM (stick #2) in the next motherboard slot.
If this RAM stick has errors repeat step #2 using a known good stick if possible, or another stick.
If this RAM stick has no errors and both sticks failed in slot#1, test RAM stick #1 in this slot.
4. If you find a stick that passes the test, test it in all the other motherboard slots.

If Part 2 testing shows errors, and all tests in Part 3 show errors, you will need to test the RAM sticks in another computer and/or test other RAM in your computer to identify the problem.

In this way, you can identify whether it is a bad stick of RAM, a bad motherboard, or incompatibility between the sticks.

So it BSOD-s in this particular game? no other? Do you monitor the hardware temperatures?

Those are a bit high.

What are the temps at normal usage or suppose the time after you just booted the computer after several hours?