Hello Annie,

Thank you for posting your request here and I'm sorry to hear about the problem you're having.
If you have installed or reinstalled your optical mouse, please follow the steps outlined below.

1. please click StartStart button, type appwiz.cpl in the Start Search box, and then press Enter.

2. User Access Control permission if you are prompted for an administrator password or to confirm, type the password or click Allow.

3. In the list of installed programs, select Microsoft IntelliPoint, and then click Add / Remove.

4. Please follow the instructions to remove the software.

5. Download and then reinstall the software. To do this, visit the following Microsoft Web site:

http: //www.microsoft ...

If you need help or additional questions, please let me know.

Truly,

Christian