In fact, in the Win 7 system, AppData has three subfolders local,locallow,roaming.
When you unpack the package, if you do not specify the path, the system will be compressed packets to the Localtemp folder, storage of some decompression files, installation software from here to fetch data, especially some graphics software, the volume is very large, occupy a lot of space.
Locallow is used to store shared data, and the files under these two folders are cleaned up by the Master optimizer, which can generally clean up useless files.
Roaming folder is also stored some of the use of the program generated data files, such as space to listen to music, login numbers, etc. and cached some of the data, these data optimization master is not removed, you can open the roaming folder in the files selected click Delete, delete the option to skip, But when you use the program again, the folder starts to swell, and the data is cached.