I'm running WIndowx XP Pro - SP3 on a Dell Dimension Desktop Computer - lately it seems that the computer is running in slow motion, but only sometimes. Starting programs takes a while, right clicking causes a delay - its like the computer has to take time to think about what I'm doing before it lets me do it - it seems that once I start doing something then I'm ok, but getting there is like walking through wet concrete.
I've run a complete scan using Norton Internet Security (with latest updates) which came up clean. I've run a complete scan using the latest MalWareBytes, which also came up clean.
I'm looking for the next step of advice. Any help would be greatly appreciated.