With the onset of March 23, 2015, Google AdWords will start removing all those ads which have not accumulated a single impression or have been removed for more than 100 days. This announcement featured on AdWords Help Center also states that once such ads are removed, you won’t be able to access them at all.
This move by AdWords will end the complexities of your AdWords account so that you can have a better experience while working with it.
Here is an example from Google AdWords to make this clearer —
Say you created an ad to attract customers to your website. But after one week, you didn’t have a single impression. After brushing up on some AdWords Best Practices, you chose to remove the ad and start over from scratch. This happened over 100 days ago, but the ad is still visible in your account history. Even though it’s not always visible in your account, your unused ad is slowing down your experience with AdWords. With our newest change, these ads will be deleted from your account permanently, meaning that they will no longer be visible or accessible in any way.
Removal of Unused Ad Groups & Campaigns
Later during this year, the simplification process will expand and AdWords will start removing all those unused ad groups and campaigns that haven’t got any impressions, or have been cleaned up past 100 days.
Similar to the ads, you won’t be able to access or reactivate any ad group or campaign once they have been removed or cleaned up from your account. In addition, even the editing of these campaigns or ad groups in your account will not be possible once they have been cleaned up.
However, it is noteworthy that if you have removed an ad group or a campaign that you are likely to access or use in the future, then make sure that you set its status as “pause”. For more information on this update visit AdWords Help Center.