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How to backup and restore data, program and system files for Sage 100

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Backing up and restoring system and data files


CAUTION: Sage Customer Support does not assist with issues related to third-party products or enhancements, hardware, report customizations, state or federal tax-related questions, or specific accounting questions. Please get in touch with your Sage business partner, network administrator, or accountant for assistance. Please refer to our Scope of Support document for details.


  • Restoring individual system data files is not a supported process with limited exceptions.
  • With the encrypted fields introduced in Sage 100 versions 2018 and higher, Payroll will be out of synchronization with MAS_SYSTEM files if they are not restored together. This will cause errors and most likely prohibit access.
  • Because all modules post to General Ledger and some modules also post to other modules, we recommend restoring the entire Sage 100 system, rather than just one or two modules. That can be usually done by restoring the entire "..\MAS90" folder and contents from backup.


Program and Data Files and Folders: All the files and folders at and below the live "..\MAS90" where Sage 100 is installed, should be backed up on a regular basis, including all company data files, system data files, and program files.

  • Note: If you do not know where on the server Sage 100 is installed:
    1. From the Sage 100 Desktop, open File, Run, and enter the following command: *INFO
    2. Note the directory path to the “..\MAS90” directory.
  • If program files are damaged and no backup is available, reinstall the affected module and the most current service update.


Company Data Folders and Files: As of Sage MAS 90 and 200 version 4.0, data folders are located under a single folder for each Company Code.

  • Example: Data files for ABC company would be located in "..\MAS90\MAS_ABC" - or in the "MAS_ABC" database if using Sage 100 Premium edition (formerly MAS 200 SQL).


Alternate Directories, Paperless Office, Premium edition, etc:
Some data files are stored in another location, such as Paperless Office PDFs or company data designated in Alternate Directories.
Sage 100 Premium edition stores most system and company data in a Microsoft SQL database.

  • Alternate Directories or Locations: Check if company data (for a specific company code) is stored in an alternate directory or Data Location:
    1. Open Library Master, Main menu, Company Maintenance
    2. For Company Code, enter the company code
    3. Access the Preferences tab
    4. Note the Data Location and Payroll Data Location (if Payroll is activated) to see if it is different from the "..\MAS90\MAS_XXX" location where Sage 100 is installed (XXX = company code)
    5. Close Company Maintenance
  • Paperless Office: Check if Paperless Office is enabled and note PDF Directory paths:
    1. Open Paperless Office, Setup menu, Paperless Office Options
    2. Note the options selected for Enable Electronic Delivery and PDF Storage
    3. Close Paperless Office Options
    4. Open Paperless Office, Setup menu, and each Maintenance task window:
      • Journal and Register Maintenance
      • Period End Report Maintenance
      • Report Maintenance
      • Form Maintenance
    5. Lookup and examine the Lists for each Maintenance task window
    6. Note the PDF Directory path for each setting in each lists
    7. Close each Maintenance window opened
  • Premium edition: The Microsoft SQL databases for Sage 100 Premium edition should be backed up regularly and tested. For more information, inquire with your SQL database administrator
    • MAS_System database
    • MAS_XXX databases (XXX is the company code)
  • All users must exit Sage100 before backing up or restoring data.
  • Services or programs such as the Sage 100 Integration Engine (formerly Sage MAS 90 and 200 Integration Engine), e-Business Web Engine, and the Sage 100 service or application (for Sage 100 Advanced or Premium editions) should also be stopped. Review processes in Windows Task Manager to verify all Sage related processes are stopped.

Use any reliable backup program to back up and restore Sage 100 using the instructions for that program.
Sage cannot endorse specific backup methods or software. Contact your network or computer technician for the method that best suits your needs.


Note: Below is a grid of typical folders under the "..\MAS90" folder and their descriptions. This is not an inclusive list, and some folders may be added or removed on different versions.

  • Two character folder names contain program files
    • Example: "..\MAS90\AP" for Accounts Payable module programs)
  • Five character folder names contain data files
    • Example: "..\MAS90\MAS_ABC\APABC for Accounts Payable data files for the ABC company).
  • Folders that do not meet the above criteria are usually system folders.
    • Example: "..\MAS90\MAS_SYSTEM" holds crucial system files, tax setup files, Paperless Office settings, etc.)
Directory Description
  Data Folders
\MAS_ABC Main data folder for company ABC (Version 4.00 and later). Individual data folders are located under this folder (except for alternate directories). On earlier versions, the data folders resided directly under \Mas90.
\APABC Accounts Payable data for company code ABC
\ARABC Accounts Receivable data for company code ABC
\GLFDD General Ledger data for company code FDD
\IMABC Inventory Management data for company code ABC
\SOSYZ Sales Order data for company code XYZ
\PRABC  Payroll data for company code ABC
  Program Folders
\AP Accounts Payable program files
\AR Accounts Receivable programs
\IM Inventory Management programs
\GL General Ledger programs
\VI Visual Integrator programs and data files
\PR  Payroll programs
  System Folders
\BIExplorer Business Insights views
\Ddicts Data dictionary files
\Help Help files
\Home System program files and system data files
\HTMLOut HTML files for Business Insights Dashboard
\Images eBusiness Manager image files
\Launcher Program and data files for the business desktopXXX
\Soa System programs and system data files (legacy)
\MAS_System System programs and system data files (Business Framework)
\Tutorial Program files for tutorial
\Wksetup Workstation Setup installation files

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