I have a MSI 683GT DRX and i have had it for about 3 years, a couple months ago i got this Error PXE-E61: Media test failure, check cable. While my laptop still booted and worked fine a new issue came up shortly after and that was random reboots. Sometimes it would reboot while i was on google chrome and sometimes while i was gaming, over time the restarts have gotten worse, some times it will restart as soon as i turn on my laptop.
I have tried a number of things to fix it such as
-Changing the boot order in my bios
-Turning off speedstep
-Reinstalling windows
-Tested my video ram
-Tested my ram with memtest 86x
-Did a recovery back to factory fresh settings
-Tested my power adaptor
-Did a 16 hour benchmark to test the graphics card in which did not restart
-Tested the CPU no errors found

Leads on to what might be causing the problem
-I did get a blue screen of death 050x000000000 which from what i read has to due with the ram.
-I did however find a boot error in my hard drive, which also could have effected the recovery.
-Will not reboot in the bios
-Restarted a lot when i was trying to go into my hard drive settings and change the amount of GB's for each hard drive.

From what i have found and i believe it may be an issue with the hard drive in which would be an easy fix for me, however i want your guys take on also what might be causing the problem from the information i have provided above.