 These OEMs commonly use a procedure known as System Locked Pre-installation, which pre-activates Windows on PCs that are to be sold via mass distribution.These OEMs commonly bundle software that is otherwise not pre-installed on Windows from Microsoft themselves, on the images of Windows that will be deployed with their PCs (appropriate hardware drivers, malware and maintenance software, various apps, etc).Individuals may also purchase OEM "system-builder" licenses for personal use (to include virtual hardware), or for sale/resale on PCs which they build.