>> 999 file

999 file format description

Many people share .999 files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .999 file can be edited, converted or printed with. On this page, we try to provide assistance for handling .999 files.

1 filename extension(s) found in our database.

.999 - Multipass Security Data

The 999 data files are related to Multipass. 999 file is a Multipass Security Data. Multipass is a utility that will help you to remember the multitude of passwords that are rushed on any user of Internet. The Multipass seems to be no longer supported.

Data files
- / -
Multipass Security Data related extensions:
Mass Properties Exchange Data
IGOR Pro Text
Network Notepad Professional License
CBS CheckWriter NonCalc Layout
ELO Rater Data
GSTree Tree Data

Naturally, other applications may also use the .999 file extension. Even harmful programs can create .999 files. Be especially cautious with .999 files coming from an unknown source!

Can't open a .999 file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

The .999 file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:


Is it possible that the filename extension is misspelled?

Similar file extensions in our database:

MicroStation Modification Project Resource File

Operating systems currently supports the following operating systems:

Windows XP/Vista, Windows 7/8, Windows 10, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, Mac OS X, iOS, Android

If you find the information on this page useful, please feel free to link to this page.

If you have useful information about the .999 file format, then write to us!

Please help us by rating this page below.

5/5 based on 17 reviews.
Thanks for rating!
Invalid rating.