(Chinese/English)Itunes为ipad恢复模式下载固件后占用了c盘空间

昨天晚上帮亲戚重装ipad，进入恢复模式后连接itunes，下载了第一个3.55G文件后，发现后续下载空间不足。但是卸载itunes后，发现那个3.55G空间占用仍然存在，导致我c盘空间不足。想知道如何解决，以及这个下载文件的位置到底在哪？

Last night I tried to help my aunt to reinstall the ipad system.When I operated the ipad into recovery mode，linked it to my itunes for windows and downloaded the first file of 3.55G，it gave tips that the storage space was not enough. So I exited and uninstall itunes.But the 3.55G file seems not be deleted and still saved in C: now.

How should I do to delete it? And,what is the address this type of files downloaded by itunes saved?