My 7 year old Dell XPS with Windows XP has become extremely slow starting up and loading any program or doing any operation (e.g., opening folders) the first time. It's not a matter of having too many programs at startup, since there are not that many and the problem continues long after startup. Every time I do something new, including but not limited to starting a new program, it takes far longer than it should or used to. (The problem started over a year ago when I was installing some software that I don't now recall but have probably removed.) Once I am working in a program the problem disappears and speed is OK. I have run numerous checks and found no problem. Any suggestions much appreciated. Thanks.