Dad's Vista bluescreen

Operating System Windows Vista Home Premium Service Pack 2 (build 6002)
System Model HP-Pavilion GG781AA-ABA a6110n
Processor 2.30 gigahertz AMD Athlon 64 X2 Dual Core
128 kilobyte primary memory cache
512 kilobyte secondary memory cache
1918 Megabytes Installed Memory
Main Circuit Board: ASUSTek Computer INC. NARRA2 2.00
Serial Number: MS1C77S11104778
Bus Clock: 200 megahertz
BIOS: Phoenix Technologies, LTD 5.10 06/23/2007

This is occurring after a confluence of events:

--Security Update for Microsoft .NET Framework 1.1 SP1 generated a blocked Startup for executable, which wouldn't run when selected. Reinstalled without UAC to success.

--He wanted scanning capabilities on very old printer with only XP software. Tried in Compat Mode to Known Incompatibility failure, dll errors at startup. Uninstall of software package failed in Revo, SysRestored to before install but was still installed, revo'd successfully after turning off HP startups.

--Huge block of immovable System files caused Defraggler to report 56% fragmentation. Cluberti helped me PSExec Defraggler as System but only defragged to 36% fragmentation.

--I noticed SysRestore points only dated to 1/23, when previously we were able to go back months to get before an infection. Using elevated CMD I apportioned 100gb of 250gb unused HD for SysRestore without restarting SysRestore. (Points are now exhausted so should I reset?)

Dad's reporting blue screen, monitor and computer won't start. Dad had set Sleep and Hibernate to Never but I turned it back on thinking I had turned it off during troubleshooting. It was hibernating because when it finally woke up said Resuming Windows.

Tested HD, chkdsk, memtest 3 passes all day. Performance so far normal now w/sleep + hibernate turned off. Exhausted and need fresh eyes.