If you have system restore, make sure it is working before deleting anything! If the only Logitech products on your computer are the mouse and keyboard, click start, search, all files and folders, type "Logitech" into the search box, click start. Right click on one of the results. Click on "go to containing folder". With luck this folder will have everything logitech in it - but check to make sure. If the folder is all Logitech you can send the entire folder to the recycle bin. If other than Logitech files are there you can either delete the Logitech individually or, create a new folder for them, move them to it, and delete it. Run thru the whole procedure again until no Logitech files are found. I am assuming you added a new keyboard/mouse. Make sure your computer is working properly before you delete anything from the recycle bin. there shouldn't be any conflicts. After you have everything set the way you want it, it is a good idea to first, run a Registry cleaner - like "Registry Mechanic": second, check if your computer needs a defrag. If something goes totally wrong, do a system restore.