You need to be the Administrator to access some shares. On Windows Vista the real Administrator account is disabled by default and using an account that is a member of the Administrators group won't have any effect when accessing these shares over a network.
If you want to be able to access all your folders using shares such as "C:", you can enable the Administrator account and give it a password. Then configure FileBrowser to use "Administrator" in the "Username" field.
The Administrator password must be strong, otherwise your system will not be secure. We recommend using a password that has uppercase and lowercase letters, at least 1 number and at least one punctuation mark.
Follow the instructions as per Enabling the Administrator account above but replace step 2 with "net user administrator /active:no"