Bose lifestyle 48 is showing error 802,can anyone help?

Are you looking to fix that yourself? That error code is a hard drive issue. Your best bet is to send it to Bose as they will probably cover it (assuming it's still under warranty).

I'm not sure how you could go about fixing it yourself. There's some things that could be attempted, but if you are not comfortable with computers, I wouldn't attempt any of them.