Posted 14 August 2012 - 08:01 AM
I suppose you could run a virus scan if you thing something might be up--many types of malware work in the background and appear to leave very little trace from the software aspect. Or, it could just be a rogue process eating more memory than it previously needed. Which would seem more likely, since the blinking light is the only abnormality.
However, I have a friend (also into the "tech-support" gig) who claims that CCleaner is an old/outdated tool for Win7 machines and that it has caused him many problems before. Whether or not that's his bad luck, I don't know. What exactly did you scan with CCleaner?