Ok if its an older laptop that someone had before it could be that the hard disk is knackered. If you look on Ebay for a USB enclosure you can slot the hard disk into that and attach it to your laptop to test it. If it works fine then back up all the information Mr Wench wants to keep.
If it does turn out that the hard disk has done then you should be able to pick up a replacement easily enough and for much less than a new laptop. Try sites like BigPockets or Ebuyer. You would just need to reinstall the OS.