The undo tool is commonly used on computers and can be helpful when making accidental changes in Adwords. In the above example I have reversed some keyword bids, but you can reverse many things changed in adwords.
There are some limitations though, the update you have made does not come up in the change history straight away so you may have to wait if you want to reverse something straight away and in a lot of cases the undo button is not present due to other changes that have been made to the account. When it is not possible to undo something, I recommend adwords editor if you want to make bulk changes.
About the author
Thomas Green is a Certified Adwords Professional and specialises in direct response marketing. He has over 6 years PPC experience and has a straight forward approach to what works and what doesn’t!