1. Run regedit
2. Go to HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Common (repeat for muliple versions of MS Office)
3. Create a KEY called "Security" here by right clicking on the Common key and selecting New->Key and typing "Security"
4. Create a DWORD in the Security key by right clicking on Security, selecting New->DWORD and type in "DisableHyperlinkWarning"
5. Change the value of this DWORD to 1