回複：謝謝你，我這麽知道那些是圖象文件和下載文件呢？ 我實在

That depends on how you are using your PC.

Usually, graphic file take a lot of space. By looking at the file extension, you can identify which are graphic files. For example, myfile.doc is MS word file and myfile.jpg is a graphic file. Go to the link below to see a site explaining the file extension

http://www.stack.com/file/extension

Use PC's "search" to search .jpg, .gif, .tiff. etc. to locate the graphic files, and view details for file info, but note that the date description of the files be later than your systems' installation - don't remove your system and application default files installation!

Also, disk slow may be caused by other problems - could be spyware or worm flooding in your disk.