Question about laptop

So I have an HP laptop. Bought it last June for $600, and I got a 2 year warranty on it. Few days ago, I left for my boyfriend’s house, came back the next day, started up my laptop, and it tells me “Boot device not found. Please install an operating system on your hard disk.” It was working perfectly the day I left. Either someone damaged it while I was gone, or there was a malfunction.

Can I go back to the store and return it and get my money back since I got the 2 year warranty, or is my only other option them to send a replacement laptop? I don’t really want a laptop anymore, and I’d rather just get my $600 back and buy myself a tablet. I’m pretty pissed off because I’m a college student. I need SOMETHING that works.