Why it happens
- Corrupted or incomplete installer files
- Blocks or restrictions from antivirus, firewall, or folder permissions
- Leftover registry or file remnants from older Office installs
How to fix it
- Disable antivirus, firewall, VPN or proxy temporarily
- Run Microsoft’s Office Uninstall Support Tool to remove all existing Office leftovers and restart your PC
- Ensure Windows is fully updated
- Download a fresh Office 365 installer from your copyright
- Right‑click the setup file and choose “Run as administrator”
- If the installer still fails, repair the Click‑to‑Run engine via Control Panel → Programs → Microsoft Office → Change → Repair
- If issues persist, create a new local administrator account and install Office from that profile
For a full step‑by‑step walkthrough and advanced troubleshooting tips, refer to this Office error code 1307 fix guide.