Many thanks for the tips Bill2.
There is only one entry under the Startup tab that I am suspicious of:
JMB36X IDE Setup
...but it seems to be a RAID driver
I've a different registry cleaner and along with Spybot I've done a pretty thorough clean.
Perhaps I'll try reinstalling .NET framework. I'll probably wait for a little while first though to see what other tips come up on this thread.