Files with cu_ file extension could be in the past found as compressed files from Microsoft WinHelp platform.
Software that open cu_ file
CU_ file extension - Microsoft Windows Winhelp compressed data
What is cu_ file? How to open cu_ files?
The cu_ file extension was used in some previous version of Microsoft Windows for one of the compressed files utilized by WinHelp.
Microsoft WinHelp is a proprietary format for online help files that can be displayed by the Microsoft Help browser.
This cu_ file type entry was marked as obsolete and no longer supported file format.
This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types (like documents, projects etc.) that were replaced in higher versions of their original programs.
The default software associated to open cu_ file:
Company or developer:
Microsoft Corporation
A family of operating systems developed by the Microsoft Corp. The first Windows was released in 1985 as a GUI add-on to MS-DOS. MS-DOS based Windows versions were developed to 2000, when was released the last version called Windows ME. Windows based on NT core started in 1993. Windows NT family are developed to these days, the latest version is called Microsoft Windows 11.
Company or developer:
Microsoft Corporation
Microsoft Windows Help is used to create help files for Microsoft Windows operating system and other Microsoft applications. Windows Help SDKs are different for every version of Windows it can be called Windows Help, Help and Support Center, Assistance Platform 1.0 Client - Windows Vista Help SDK, Microsoft Windows: HTML Help 1.4 etc.
List of recommended software applications associated to the .cu_ file extension
Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.)
and possible program actions that can be done with the file: like open cu_ file, edit cu_ file, convert cu_ file, view cu_ file, play cu_ file etc. (if exist software for corresponding action in File-Extensions.org's database).
Unspecified and all other actions for computer programs working with cu_ file - Microsoft Windows Winhelp compressed data
Click on the software link for more information about Microsoft Windows. Microsoft Windows uses cu_ file type for its internal purposes and/or also by different way than common edit or open file actions (eg. to install/execute/support an application itself, to store application or user data, configure program etc.).
Microsoft Windows:
Main software associated with cu_ file by default: Microsoft Windows
Microsoft Windows Help