How do I stop a user from accessing a file?

You can log on to DriveHQ.com website or DriveHQ FileManager client software. On the website, you can simply click Manage Shares (on top of the webpage above the page header) to see a list of folders you shared. With FileManager, you can click the Tools munu, then select Manage My Shares. To stop sharing, you just need to delete the Share. You can also edit an existing Share (e.g. add/remove one user from the Share-to field; change Share permission, etc.)