It turns out that the normal way to access safe mode is disabled in Windows 8 Developer Preview.
Instead, launch Windows, and do the following:
- Call up the ‘Run Dialog‘ by hitting WinKey+R
- Enter ‘msconfig‘ and hit enter
- Go to the ‘Boot’ tab
- Enable ‘Safe Boot‘ under ‘Boot Options’
- Restart your machine
To return to normal mode, just run the same process, and un-check ‘Safe Boot’