Turning off CEIP in Windows XP, Vista, 7, and 8.1 is not easy.
In XP and Vista, click Start > Control Panel > System and Maintenance > Problem Reports and Solutions. On the left at the bottom, click Customer Experience Improvement Program Settings. In the resulting dialog box, check "I don't want to join the program at this time" and click OK.
In Win7, type "Experience" in the Start menu search bar; in Windows 8.1, type "Experience" on the Metro Start screen. In either case, click on Change Customer Experience Improvement Program Settings. In the resulting dialog box, check "No, I don't want to participate in the program," then click Save Changes.