If you are getting the blue screen with a cryptic message, write down the error code, and then google the error code.
If your network card on your computer is going out, you can purchase a usb adapter (wireless or wired). But if your computer is crashing, or your display screen is goofing up, see what's causing that before you spend any money on new parts.
And like already mentioned, it could be your router, causing the internet problems.
Wayne Sallee
Wayne@WayneSallee.com