Why is it that my computer only recognizes my CF Card about half of the time. Now it wont even recognize it at all. even after several restarts. is this a pc issue or a Lexar issue?

Are you using an internal or external card reader, and does it read other cards normally?

Are you putting the card in the reader upside down?

Your card could be malfunctioning, a lot of Cf cards seem to have problems for 404 users.

using the built-in slot. was recognizing it yesterday but not today. I am thinking that its my slot, not the card. I don't have another card to test the slot though.

You could buy a cheap usb cf card reader.