You are getting the 0x116 TDR error, more info:
STOP 0x116: VIDEO_TDR_ERROR troubleshooting
1.
- Boot into safemode with networking
- Uninstall the Radeon
drivers
- Use
driver sweeper to remove leftover ATI Radeon driver files
- Install latest drivers
Latest Radeon Drivers
- Reboot into normal mode
2. If the above does not work test your RAM, do at least 7 passes
RAM - Test with Memtest86+
Replace your RAM if errors are reported in the test
3. If no errors are reported replace your HD5850
Code:
BugCheck 116, {fffffa80056304e0, fffff88004083008, 0, d}
Unable to load image \SystemRoot\system32\DRIVERS\atikmpag.sys, Win32 error 0n2
*** WARNING: Unable to verify timestamp for atikmpag.sys
*** ERROR: Module load completed but symbols could not be loaded for atikmpag.sys
Probably caused by : atikmpag.sys ( atikmpag+7008 )