No it has been doing it a year now, before windows washer was installed. Is is just like ccleaner, freeing up hard drive space.
Avast was only installed last week in an effort to increase the chances of finding the problem so running 2 anti-virus programs is not the issue either.
ccleaner has a registry cleaner which I have run but makes no difference.
As I said, it will sometimes start normally... I guess 25% of the time.