It is a summary of the thread for your reference.

Issue: Cannot install Office 2007 SP1 update. Error 78f (error 1935).

Suggestions:

If you are using a pre-installed office 2007 and NEC computer, please insert a CD in the CD-ROM and try to update SP1 again.

This method doesn't fix the issue for Chris on this thread.

1. Repair Office 2007.
2. Check the Latest version of Windows installer.
3. Check the free disk space on C:\.
4. Download MSICUU2.exe to remove .net framework.

The above steps don't fix the issue for Chris on this thread.

5. Uninstall Office 2007, reinstall Office. SP1 was installed successfully.

Thanks.

Emily Lin