Glad I could help then. Yes for Windows 7 full access to C: you would need to "Edit" then Add the "Everyone" share then add check marks for full control etc. The settings I showed were for Windows 8 which is different than Windows 7.

Directions for Windows 7 >. HDD sharing - Windows 7 Help Forums

The access denied message is typical and you normally will need to click through various levels of security as the new settings cascade through the file structure. Basically just click yes to approve each new setting as it's applied through the file structure.