so basically youre saying, youre hoping its a software bug
Keeping non system files on a system drive is playing with fire, especially with windows
If you value those files, Id be looking into a means of backing them up. I lost some Valentines Day Pics in 2003 when a HDrive fried, Im still in trouble over it
As for the SCM. It could be a problem, sure - but youd need to give us more info about what the log is saying and what services may be affected, and/or when the SCM is messing up. It quite often does it during startup, but good to clarify
Have you added/removed any programs recently, particularly ones that have sone type of networking/access component in them?