Notes about the 999 file extension:
To open this file type, a required software must be installed. Without it you only see a Windows message "The following file cannot be opened
" (Windows 7) or "How do you want to open this file?
" (Windows 10) if you double-click the file. There click on "More apps"
and choose a suitable software to view such files on your PC or from email attachments.
The 999 file type is primarily associated with 'Multipass Security File'.
Detailed information for file extension 999:
Other applications associated with file type 999:
- Sage (Backup) by Sage SoftwareThe Sage Software family assists small and medium-sized businesses with a wide range of business management applications and services. This association is classified as Archive. The identifying characters used for this association are - Hex: 53 41 47 45 42 41 43 4B 55 50 , ASCII: SAGEBACKUP
'Identifying characters' used on FILExt.com are
provided by Marco Pontello from his TrID database
To change file associations press Windows Key
and then Apps and Features
> Default apps
> Choose default apps by file type
Invalid file associations could be the result of underlying issues within your Windows PC.