My AppData folder is growing all time and now 15GB. Can I delete it without problems?

This AppData folder is built for backward compatibility and maybe its size is increasing because you have lots of files and softwares on your operating system and you are updating windows regularly so don't worry about its size.

Hi, I’d like to share the following for you about the Appdata: http://technet.microsoft.com/en-us/library/cc766489(WS.10).aspx We can see Win7 has a new Users Folder which replaces XP’s Documents and Settings. Within the new folder structure, Win7 has a folder called plain ‘Documents’, which replaces XP’s ‘My Documents’ folder. The most important new subfolder is AppData. Also to maintain backward compatibility, Win7 has shortcut links to the old XP folders such as Local Settings and Application Data. So I don’t recommend to do that with no experience in the case.Because, such action may cause applications can't work normally. And if you think the size of the floder is too large for your computer. Please inspect subfolders, check the size of them. Then post some details for the folders which you think takes too much space. So that we can analyze the cause of the problem. Hope that helps