SuperFetch ( previously known as Memory Prefetcher, now it is called SysMain ), is a Windows service that makes your frequently-used programs load faster by preloading them into RAM. However, Superfetch can sometimes take up too many system resources (such as CPU, memory and storage). When the computer run out of memory, it is good idea to disable Superfetch and other unnecessary services. iSumsoft System Refixer is a reliable tool for disabling unnecessary services to reduce CPU and free up memory usage, thereby optimizing the computer's memory.