C00 is a file extension used for files that are a part of larger archive created with WinAce tool. In order to recreate the whole archive, all the other split archive files are needed, that is files with extensions C01, C02, C03, etc.

The number of parts the original archive is split is determined by its size – the size of C00 part must be set by the user and will determine the size of the rest of the parts. Last stable version of WinAce was released in 2007, when the software was discontinued.