• Change Registry Settings
• Rename Office Files
• Clean Temporary Extracted Files
• Repair Registry
• Use a Different Product Key
• Uninstall the Existing VersionRepair Registry

Change Registry Settings

Microsoft Office installation data is located in the Registry. If this data has been changed by other programs, you receive error 25004 during Office installation.

• Click the Start button. Point to All Programs | Accessories | Run.
• Type REGEDIT in the Open box. Click OK.
• Registry Editor opens. Locate following Registry path:
  HKEY_CURRENT_USER | Software | Microsoft
• Delete the “Office” sub key. Click Yes button to confirm. Close Registry Editor.

Rename Office Files

The files located in the Microsoft Office program files directory should be renamed in the following manner. Some of them could be corrupt. Renaming these files would force the setup to copy them again.

• Double click My Computer desktop shortcut.
• Open C:\Program Files.
• Rename following folders with the new names specified:
  Microsoft Office as Microsoft Office Backup
  OfficeUpdate as OfficeUpdate Backup
  OfficeUpdate14 as OfficeUpdate14 Backup
  OfficeUpdate 12 as OfficeUpdate12 Backup

Clean Temporary Extracted Files

Before Microsoft Office is installed the setup program copies installation files to your hard disk. These files are used during the installation task. If these files are corrupt, you receive error 25004.

• Click Start | Run. Type %TEMP% and press ENTER.
• Empty the Temp folder.

Repair the Registry

Registry Errors is the most common reason behind error 25004. Use RegInOut Registry Cleaner to scan all Registry hives. A list of error appears. Click the “Fix Errors” button to repair them.

Use a Different Product Key

Type a different product key or install Microsoft Office as trial version. This shall fix error 25004 if it associated with the product activation.

Uninstall the Existing Version

Do you have an older version of Microsoft Office installed? If you’re trying to overwrite the older version or keeping two versions simultaneously it may result in error 25004.

• Click Start | Control Panel.
• Click Programs | Uninstall a Program.
• Select Microsoft Office, click Change. Select “Uninstall this program” and then click Next.