In internet explorer 8:

1. Click "Tools" in the file menu.
2. Click "Delete Browsing History"
3. Select The type of files you wish to delete: Usually just temporary files.
4. Click "Delete" at the bottom of the dialog box.

In Fierfox:

1. Click "Tools -> Clear Recent History"
2. Choose the time Range to delete
3. Click "Details" and make sure that "Cache" is checked.
4. Click "Clear now"

In Chrome:

1. Select the Tools Menu (Wrench Icon)
   
2. On the "Under the hood" tab, select Clear Browsing data.
3. Select the Empty the cache check box
4. Select your desired time frame.
5. Click the "Clear Browsing Data button"