To give yourself rights to a folder, double-click the folder in Windows Explorer. You can also modify rights in the security ...

To give yourself rights to a folder, double-click the folder in Windows Explorer. You can also modify rights in the security tab of the folder. If you want other homegroup members to be able to access it, share it with the homegroup by clicking the folder and choosing Share with.  Windows prevents you from sharing entire drives (for example, drive C) and some system folders (for example, the Windows, Users, and Program Files folders).