Blue screen crashes are OS kernel failures. Yes, often they have a hardware issue like a HD drive thats going or a bad RAM chip (module).

Have you tried running any HD or memory diagnostics? I would first make a full backup of your HD before proceeding. Did something show up?

If nothing showed up - Do you have the system recovery CD/DVD the system came with and/or the OS & App installer disks or image files. If you do I would reformat the HD and install a fresh copy of the OS and install from the original sources (CD or download) your applications, don't forget to update both (OS & Apps) with any needed patches.

If you did get an error you'll need to address what hardware failed.