I've recently been fixing up my old (4 years old - nearly) Dell Inspiron laptop (new Hard Drive, Battery, etc) and after a couple of weeks - the screen had started to become light gray, and when I was fixing my laptop up I hadn't touched the screen at all. A couple of weeks later, the screen had totally inverted.

I'm hoping its just the matter of replacing the screen, and not the motherboard failing because the system works fine.

Nah the motherboard is fine. But something is wrong with the integrated graphics card, the graphics drivers, or physically with the screen. If the motherboard were failing, you wouldn't even be able to get to the login screen. BUT! There is however a scenario where you might need a new board or new computer. And that is if there's something physically wrong with your graphics chip. For a computer that old, that's a death sentence. For now, let's hope it's just a driver or screen problem.

This is a link to a graphics driver update for your model laptop from the Dell site:
http://support.dell.com/support/dow...typeid=-1&dateid=-1&formatid=-1&fileid=170751

And here is the list of drivers for all your other potential needs:
http://support.dell.com/support/dow...gen&SystemID=INSPIRON1300/B130&os=WW1&osl=EN#

I didn't post a driver for the monitor because I have no idea what specific model screen you have. If you click the plus sign next to the display driver section, you can see there are...well...quite a plethora. So unless you can give me far more detailed information regarding your specific screen, you can feel free to browse that section yourself. Heheh...

If the driver update doesn't fix this...inverted screen...thing..., or a new screen doesn't do you any good, then it might end up being your worst nightmare .

I'm going to replace the screen as some dead pixels are now showing up on the screen, I'll just use an external monitor for the time being.

Thanks