Removing Outdated Microsoft Project COM Type Library Entries

Background:

Uninstalling a version of Microsoft Project can leave behind “orphan” System Registry keys. These outdated COM Type Library entries can prevent DTS add-ins from working correctly with Project. Symptoms may include:

• Application-defined or object-defined error

• Automation error: Library not registered

• Error in loading DLL

• Could not contact the Microsoft Excel application

• File name or class name not found during Automation operation

• Object variable or With block variable not set

• Missing or incorrect results graphs

To restore correct functionality, remove outdated COM registrations by following the procedure below.

Remove Outdated COM Type Library Entries (Requires Admin Rights)

1. Close all applications

Close Excel and Microsoft Project.

2. Open Registry Editor

1. Click Start » Run

2. Type REGEDIT and click OK

3. Search for the Project COM key

1. Click Computer at the top of the left panel

2. Press Ctrl+F and paste the following key (including brackets):

{A7107640-94DF-1068-855E-00DD01075445}

3. Select Keys and Match whole string only.
   Clear Values and Data.

If the Key Does Not Exist

Project may be able to recreate it.

1. Close Registry Editor

2. Open Microsoft Project (no file needed)

3. Close Project

4. Reopen Registry Editor and search again

If the key still does not appear, see Microsoft Project Installation below.

If the Key Does Exist

4. Identify outdated versions

Expand the key. You may see entries such as:

• 4.5 – Project 2003

• 4.6 – Project 2007

• 4.7 – Project 2010

• 4.8 – Project 2013

• 4.9 – Project 2016

Delete entries that do not match the version(s) currently installed.

5. (Optional but recommended) Export for backup

Right-click the main key
{A7107640-94DF-1068-855E-00DD01075445}
Select Export, and save the .REG file.

6. Delete the outdated entries

Right-click each incorrect 4.x key → Delete → Confirm.
Repeat for all mismatched versions.

7. Search for additional instances

This key can appear multiple times.
Press F3 to jump to the next occurrence, and repeat steps 4–6.

8. Close Registry Editor

Open @RISK and verify you can import .MPP files.
After confirming operation, you may delete the backup .REG files.

Microsoft Project Installation Issues

If Project does not recreate the key:

1. Verify Project is updated to the latest service pack.

2. In Control Panel » Programs and Features, run a Repair:

   • If Project appears separately, repair it

   • If not, repair Microsoft Office

3. If problems persist:

   • Uninstall and reinstall Project

   • Or uninstall and reinstall Office (if Project is included in Office)

If the Issue Involves Excel Instead

Incorrect Excel COM registrations may produce similar symptoms.
See Removing Outdated References to Office from the System Registry for the procedure.