HDMI Support My Philips model: 50pf7320a/37, dose not always support the HDMI connection from my cable box. The Cable provider is Brighthouse, the cable box is Explorer 8300HDC. The error code is (GS511_HDCP_DLG).

If this doesn't help, there may not be much hope for you.  There are some ambiguities in the HDCP protocol (rights protection for HD).  When two devices use this one will send a message to the other, it then waits for a response, lastly it responds back.  This is the connection setup procedure.  The issue is that there wasn't a specified time limit that a device must wait before assuming the connection isn't working.  This can cause you to get an error message along the lines of "your tv doesn't support hdcp"  Unfortunately, there's not much that can be done about this.  I spent the better part of two weeks researching this issue trying to figure it out.
As for formatting your usb key, you should be able to go into my computer, right click on the drive then click format.  It should give you some options as to how you want the format done.

Follow this link dowload the software upgrade for your tv and procced to install this can help to solve the problem
http://www.p4c.philips.com/cgi-bin/dcbint/cpindex.pl?ctn=50PF7320A/37&scy=US&slg=AEN&searchtxt=50PF7320A
Your rating to my answer is highly appreciate
Thanks