Limit RAM Win 8.1 x64 bit

I recently downloaded After Effects and I wind after a half hour of work began to shout that the operatives are few and wanted to close the AE,but I refused the cancel button.Then what would make a normal text, I decided to go to photoshop and he krasnolese,and the Vind yelled back that memory a little.I go into Sony Vegas to crop and Severstalavto MP4 to MP3,but it crash and Windows you have probably guessed,I started to do.Then it closed itself and After Effects.So I go in task Manager and see what AE three gigs took(well, I wasn't surprised...yet).I go into the category of Productivity and see it




I saw something similar,but there they had a limit even in computer properties,and I have only in task Manager.
And no,I haven't played Assassins creed unity on high,so operative clogged.

I hope for your help