There is actually a game bug that causes that to happen but I don't think that's the problem
Firstly there are at least 2 things that can cause you grief on a laptop.
The main one is that windows is self destructive on laptops unless you are aware of how things work.
Meaning if you use sleep and/or hibernate, this has never ever been working as intended and will lead to minor disk problems, usually seen as incorrectly allocated free space and if it is not repaired on a regular basis will cascade. the result being many things that are being written to disk will actually vanish or get lost.
You have to force a diskcheck to get windows to discover this as it is very unlikely to catch it on its own unless windows actually crashes, even then it may not see the actual error.
That said, rather than cleaning up windows which is good to do anyway if done by someone that actually knows what they are doing, a better solution is to do a windows repair from the installation dvd, if you can't do that then a re-install should do fine.
If you still have the issues after doing these, another possibility is that some contacts have become oxidized which is very likely after 2 years of use.
This is reasonably simple to fix by removing the ram and cleaning the contacts with a new pencil eraser. there are many ways, but this works quite well and is cheap and fast. In doing this you will see very clearly that the contacts become very bright and shiney once again.
It is unlikely that there are any other cards or devices in your laptop that have removable parts like the ram is, but if there are, for example mram or variations, then they also may require cleaning.
Hopefully this helps.
