The Disk Cleanup in my windows7 does not work. If I open the disk cleanup, select the files and click delete and open disk cleanup again, I find that the files are still there. Please, somebody help. Can I uninstall and reinstall Disk Cleanup?

In the Start menu, click All Programs, click Accessories, click System Tools, and then click Disk Cleanup. Disk Cleanup will automatically begin to scan your disk for files you can delete. Note: If the Disk Cleanup: Drive Selection dialog box appears, select the hard disk drive that you want to clean up, and then click OK. Click the Disk Cleanup tab, and then select the check boxes for the files you want to delete. When you finish selecting the files you want to delete, click OK, and then, to confirm the operation, click Delete files. Disk Cleanup then removes all unnecessary files from your computer. Hope this helps.