I searched the web, and the MS knowledge base. I've installed a couple of "helpful" programs that didn't work. I uninstalled and re-installed the correct software, and checked for a update for my 4 month old MS wireless laser mouse. The scroll wheel won't scroll anymore! I see where lots of people have had the same problem with other brands, but I can't find a software fix that works. Anyone here who can help would be an angel! If I could find the receipt, I'd take it back to the store for a replacement. I do believe I registered it online, though; I usually do. It is just sitting there, with its non-existant tail tucked between its legs. I think it must be the hardware. Grrr.