Microsoft Knowledge Base

Microsoft Knowledge Base was (as of 2020, almost all articles now produce the message : Sorry, page not found) a repository of over 150,000 articles made available to the public by Microsoft Corporation. It contains information on many problems encountered by users of Microsoft products. Each article bears an ID number and articles are often referred to by their Knowledge Base (KB) ID.
kbalertz.com was a website that provided email alerts of new articles, although Microsoft recently has provided a similar service.