I spoke too soon
Within a couple of days it was back to the gentle climb to 100% CPU and the inevitable crash within a minute of starting a call..
I uninstalled it, and then checked to see what was left.
- One large folder called C: \Program Data \ Skype with subfolders and various stuff. Removed that.
- Over 70 entries in the Registry, including over 30 in "Firewall Rules", most of them apparently identical. Removed all those and restarted the PC. It was VERY slow starting (obviously didn't like the gaps) but gradually worked its way down to 2% CPU use - lower than I've seen in a while.
Does anyone know if there should be so many Skype entries in the Registry? I've been using it for years and like the ease of use (and I have a fair bit of Skype-out call credit) but I don't want to put it back if it's going to gum up the PC again.
Basically, with it installed, anyone in my callers list can crash my PC just by Skype-calling me. Not impressed with that!