BSOD Occurs At Random Intervals While Browsing (Firefox)

Full scans performed with both Malwarebytes and Microsoft Security Essentials. Nothing found.

I followed the instructions on deleting/recreating a pagefile

I scanned for missing, modified or corrupted Windows files - Windows Resource Protection did not find any integrity violations.

I've noticed that since I have tried the driver verifier, my computer freezes more often. It is usually under the same circumstances as the BSOD would be - browsing with Firefox, potentially numerous tabs open.

Driver Verifier may cause slight freezing and 'lag' since it is stressing the drivers, in order to produce a BSOD which will hopefully point out a driver which is causing the problem.

Update:
Startup repair has been running for the night. It came about from the frequent freezing upon start up and hard boots.
Are one, or both, of my hard drives failing?
What are my next steps?

Update BIOS (if possible):

Code:

American Megatrends Inc. 1206, 05/06/2012

• How to Update Your BIOS | PCWorld

Run Driver Verifier to scan for any corrupted drivers which may be causing problems, this program works by running various stress tests on drivers, in order to produce a BSOD which will locate the driver; run for least 24 hours:

• Driver Verifier - Enable and Disable

Additional Help - Using Driver Verifier to identify issues with Drivers

Update:

Atheros AR9485 Wireless Network Adapter:

Code:

5: kd> lmvm  athrx
start             end                 module name
fffff880`0684a000 fffff880`06afa000   athrx      (deferred)             
    Image path: \SystemRoot\system32\DRIVERS\athrx.sys
    Image name: athrx.sys
    Timestamp:        Fri Oct 21 10:45:10 2011 (4EA13F26)
    CheckSum:         002AF1A0
    ImageSize:        002B0000
    Translations:     0000.04b0 0000.04e4 0409.04b0 0409.04e4

• ATHEROS drivers for Microsoft Windows

AMD Radeon HD 6900 Series:

Code:

5: kd> lmvm atikmpag
start             end                 module name
fffff880`04528000 fffff880`0459e000   atikmpag   (deferred)             
    Image path: \SystemRoot\system32\DRIVERS\atikmpag.sys
    Image name: atikmpag.sys
    Timestamp:        Fri Sep 28 02:12:52 2012 (5064F994)
    CheckSum:         00071DC9
    ImageSize:        00076000
    Translations:     0000.04b0 0000.04e4 0409.04b0 0409.04e4

• Latest AMD Catalyst Video Driver for Windows 7

How long does startup repair go on for?
I can't start my computer without startup repair starting.

Did you start Startup Repair yourself or does it automatically just start?

• Startup Repair

Have you allowed it to complete? If not then this may help,

• Startup Repair Infinite Loop Recovery

It automatically starts.
I am not going to allow it to complete, I don't think it should take this long.
I am going to follow the infinite loop recovery instructions.

If the computer fails over into Windows RE because of a detected boot failure, Startup Repair launches automatically.

Personally, I would allow the Startup Repair to complete, with the reason outlined above, this may also be helpful:

• 'Startup Repair' on Win7 - how long does it take?