Try to manually uninstall 2142. Here are the steps:

To delete the configuration files and local copy of your account:

1. Click the Start button on the Windows Taskbar.
2. Select My Documents.
3. Right-click the Battlefield 2142 folder and select Delete.

To delete the game files (in the default location):

1. Click the Start button on the Windows Taskbar.
2. Select My Computer.
3. Double-click the C:drive.
4. Double-click the Program Files folder.
5. Double-click the EA GAMES folder.
6. Right-click the Battlefield 2142 folder and select Delete.
7. Go to the following folder: C:\Program Files\InstallShield Installation Information (If you cannot find this folder you may have to go to Tools > Folder Settings and click the setting to SHOW hidden folders.)
8. Right-click the folder named {ED50ECE9-EC54-4C05-B5ED-EE4741A9F2EC} and select Delete.
9. Close all open windows.
10. Right-click the Recycle Bin and select Empty Recycle Bin.

To edit the registry and remove Battlefield 2142:

1. Click the Start button on the Windows Taskbar.
2. Select Run.
3. Type regedit in the text field and click OK.
4. Click File and select Export.
5. Name the file Backup and make sure the Export Range is set to All.
6. Click Save; you will now be returned to the Registry Editor window.
7. Click the plus (+) sign next to HKEY_LOCAL_MACHINE.
8. Click the plus (+) sign next to Software.
9. Click the plus (+) sign next to EA GAMES.
10. Right-click the Battlefield 2142 folder and select Delete.
11. Back under Software, click the plus (+) sign next to Electronic Arts.
12. Click the plus (+) sign next to EA GAMES.
13. Right-click the Battlefield 2142 folder and select Delete.
14. Just above EA GAMES, you will see a folder named EA CORE. Click the plus (+) sign next to EA CORE.
15. Click the plus (+) sign next to INSTALLED GAMES.
16. Click the plus (+) sign next to EA GAMES.
17. Right-click and select Delete on any Battlefield 2142 folders.
18. Click the plus (+) sign next to Microsoft.
19. Click the plus (+) sign next to Windows.
20. Click the plus (+) sign next to CurrentVersion.
21. Click the plus (+) sign next to Uninstall.
22. Right-click the key named {ED50ECE9-EC54-4C05-B5ED-EE4741A9F2EC} and select Delete.
23. A Confirm Key Delete window will appear, choose Yes.
24. Close the WindowsRegistry Editor.

Battlefield 2142 should now be completely removed from your system.

From here you may now install 2142 again. Install the latest patch. Install Northern Strike if needed. If you installed Northern Strike then reinstall the latest patch.