BSOD can mean any variety of issues, from bad hardware to corrupt system files to viruses. unfortunately it's unlikely anyone here will be able to troubleshoot what's wrong, you'll have to take it into a tech.
as far as data is concerned, it's likely you've lost anything as long as the issue isn't the harddrive itself. if the harddrive is OK then files can be recovered.
as a side note, if you end up having to repair/replace you computer, please back up your data next time (more than one copy in more than one location) and as a general rule of thumb don't trust harddrives older than 5 years.