Vista introduced this new feature called Superfetch ( and it's still present in Seven). This thing is actually what deals with your memory consumption. Superfetch detects whatever program is running and allocates the necessary amount of memory for the program to run in real time. Another little thing that Superfetch does is that while you still have free memory it detects the programs you use most often and caches them. What this means is that if by any chance you start one of those programs it will launch right away ( many times faster than XP depending on size and program) because it was preloaded into your memory. And this is another reason why most often, if you check your mem status ..you'll notice that usually it's only 1-2% free. That is because the rest is cached ( right now i have 1.4 gb of cache and only 15mb free). And luckily this works really well and in case you start a program that demands additional memory Superfetch instantly releases the extra amount.
now here's the fun part .. 2 minutes earlier Superfetch failed and crashed, windows gave me a warning. I was expecting at least a restart if not a direct system crash ..but nothing happened besides Aero being disabled :)) and Aero just came back now as it has done many times before. ( yeah occasionally it crashes and restarts after about 1 minute ..it's because of my drivers).
That's it. I'm really sorry, i know i haven't written anything good but i'm super busy and always tired when i come home, so i never really have the mood to start messing up my pc. Anyway I have a holiday next week and I promise i'll try to get up to speed. Cheers