I don't think xud's solution will work and pauln90's only works if you've downloaded the Google toolbar... try this, open the Google Search and then in the search box type "a" (without the quotation marks), then when all the searched items beginning with the letter "a" appear, place your cursor over the first item. Simply depress the "delete" key and hold it... all the items will delete in turn. Then repeat witht he letter "b", etc. There may be another method, but I haven't discovered it. This just takes a few minutes even if a little cumbersome...