As I mentioned previously, there is nothing wrong with the memory usage as it is. Windows 7 has excellent memory management and there is no need or benefit in any add-on memory cleaners, optimizers, boosters, etc. They will not benefit performance and will almost always impair it.
Modern operating systems are fully capable of managing memory on their own without the need of any help. The problem is that most computer users have a hopelessly outdated (1980's and older) concept of how memory is managed in a modern OS. Modern operating systems are designed with the concept that memory should be used to the fullest possible extent and free memory is evil. The basic concepts have been in use on large computers since the 1960's and have been fully validated. They were introduced to smaller systems in the 1990's when the hardware became capable.
I will say only one more thing regarding this: In the Microsoft publication "Windows Internals", 5th edition, the authors mentioned these memory cleaners and described how they worked. The comments were not very complimentary, quite the contrary. One of the authors is Mark Russinovich who holds a PHD in computer science and is a well known Windows expert.