Create hotspot without password

Solution 1:

• Open command prompt (in Admin mode)
• netsh wlan set hostednetwork mode=allow ssid=anything key=
• netsh wlan start hostednetwork
• Control Panel > Network and Internet > Network and Sharing Center
• Right Click Connection > Properties > Sharing > Allow other users to connect

This should get you where you need to go :)

With the key attribute in step 2 - leave it blank.

It goes without saying that there are considerable risks with leaving a blank password - anyone can connect and do anything on your connection - including try to break into your PC. That said, your question was very specific - so I'll skip the lecture on security and assume you've thought this through and definitely want to take this risk and accept the possible consequences.

Enjoy!