Windows 7 update issue

Hi.


I have installed windows 7 x86 , which i not updated and last update of my build of my windows were 2-3 years ago. My computer have 4 gb ram. Before updating my computer were used 900mb-1gb of ram in free mode, without opening programmes. When i have updated my windows, my computer on free mode using 1.6gb of ram and not my computer working slow. I have installed only important updates and 3 another display language.

Does my computer start work slower and using more ram by updating reason, or there are another think?

Thanks.