URL problem

Hi!

When I click Start, Run within my XP Professional and type my URL and click OK I’m getting an errorbox: “There was a problem sending the command to the program.” So each time I want to open an URL from there I have to put ‘iexplore’ in front of the URL…
I don’t know how to solve this!
This very same error I get when I want to activate the Search function from within the right mouse click Context Menu to do a search within a certain folder!
When I click, Start, Search I DO get the search window without any problem(s).
Any hint/tip/clue?
For the rest my systems performs ok!