.CLB File Extension

File used by Microsoft COM+, a service on Windows operating systems that allows components to communicate with each other; contains COM+ application, class, and computer-level attributes; store information that provides consistency across computer services.

CLB files are commonly found in the COM+ registration database, which is located in the %windows_directory%\registration folder. They use the naming convention R00000000000X.clb, where X is a letter or number.

File created by ICQ, an online chatting program; contains user contacts, including their unique ICQ number, aliases, and other contact information; used to create backup copies of contacts.

NOTE: ICQ for Mac, which was once available, is no longer offered by ICQ.com.