I had exactly the same problem after buying my new PC in February. I also have Windows XP and, after many enquiries and money spent, was told to do the following (and it worked!)
1) Make a system restore point!
2) download this file:
3) Double click the file and select and install the "Motion JPG" option ONLY!!!
4) Rboot your PC and try and view again..
I do hope you find it successful too as I know only too well how frustrating it is when it doesn't work properly.