With so many problems on your machine it would be a wise move to save all your valuable data while you can.
Is there a problem also with this Service not starting, Remote Procedure Call (RPC), this is the main Service which most others rely on to run?
Here is my "shopping list" of some things that I might try on the way to a probable reinstall of the operating system.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
How to repair the operating system and how to restore the operating system configuration to an earlier point in time in Windows Vista (or 7)
How to analyze the log file entries that the Microsoft Windows Resource Checker (SFC.exe) program generates in Windows Vista
How to use the System File Checker tool to troubleshoot missing or corrupted system files on Windows Vista or on Windows 7
Try running ChkDsk to check your drive for errors. Right-click your Drive icon/ Properties/ Tools/ Error Checking. Try it first by not checking either box (this will run it in a Read-only mode) to see if it flags any hard drive or file problems. If it does, restart it by ticking both boxes, and rerun it to allow it to attempt to fix any found problems.
The hard drive manufacturer will have free diagnostic software that is bootable, or that may even run from within Windows, that will thoroughly check the condition of your hard drive.
How to Use the Memory Diagnostics Tool in Vista or Windows 7
See how many unsigned drivers you have running on your machine. This article will guide you on the instructions but all you have to do is type sigverif in Start Run.
How to identify unsigned drivers using sigverif utility in Windows Vista
Have you checked for malware?
I see lots of recommendations here for programs like -
Malwarebytes' Anti-Malware
SuperAntispyware
Use the Vista instructions in this to reset to default the security settings.
How do I restore security settings to the default settings?
Solving setup errors by using the SubInACL tool to repair file and registry permissions