Windows 7:
Deleting Unnecessary Files using Disk Cleanup:
If you want to reduce the number of unnecessary files on your hard disk to free up disk space and help your computer run faster, use Disk Cleanup. It removes temporary files, empties the Recycle Bin, and removes a variety of system files and other items that you no longer need.
The following procedure cleans up files associated with your user account. You can also use Disk Cleanup to clean up all the files on your computer.
• Open Disk Cleanup by clicking Start->type Disk Cleanup->click Disk Cleanup
• In the Drivers list->select the hard disk that you want to clean up->click OK.
• In the Disk Cleanup dialog box->in Disk Cleanup tab->select the check boxes for files types that you want to delete->click OK.
• Click Delete Files in the message box.
Permanently Delete Files from Recycle bin:
When you delete a file, it's usually moved to the Recycle Bin so that you can restore the file later if necessary.To permanently remove files from your computer and reclaim any hard disk space they were using, you need to delete the files from the Recycle Bin.
You can delete the files permanently using the following steps:
1.Open the Recycle Bin by double-clicking the Recycle Bin on the desktop.
2.Do one of the following:
->To permanently delete one file, click it, press Delete, and then click Yes
->To delete all of the files, on the toolbar, click Empty the Recycle Bin, and then click Yes.
->To permanently delete one file, click it, press Delete, and then click Yes
->To delete all of the files, on the toolbar, click Empty the Recycle Bin, and then click Yes.
Windows XP:
2.Select the files by clicking the check box that you would like to delete and click OK
3.Click View Files to see the description of the selected files.
4.Click OK to clean the selected files.