If I go to task manager, I saw where all they go
Notice show processes from all users are ticked.
Now I have 8GB memory. If you look the above picture, the "greediest" program use at most 300mb of memory. So the the total is at most 2 GB. Yet if I look at the graph, task manager said I am using 7GB.
Note: Before answering, please try this in your computer first. Chance is the same problem is in your computer too all along. I have this issues in all of my computers running windows 7. It seems to be behavior rather than a bug.
The issue is basically this. There is a discrepancy between memory used by processes and memory used total. I just want some explanation. Some says memory commit but I want to see detail to strengthen my faith.