If you find that your Adwords ad has been disapproved take a look at their guidelines. Do yourself a favor and become familiar with the Adwords guidelines to save yourself time and headaches in the future.
Any violation of the rules will have you out of business as if someone flipped a switch. Sorting out why your ads were stopped and fixing the problem will become a pain. The best thing to do is to avoid it all together.
There are just some things that you are not allowed to promote. If you read the guidelines you can get an idea of what these are and avoid them all together.
It is also possible that your Adwords Ad has been rejected because they did not approve of the way your link looked or the way you have it set up. They do not like anything that looks misleading or any links that misdirect website addresses.
If your links are misdirecting, you can plan on them disapproving your ads. It is always best when promoting Adwords Ads to use a custom domain. Custom domains will keep you from having to misdirect any of your ads. It is quick and easy to set up so you might as well do it correctly. The ease of setting up a custom domain compared to the discomfort of trying to sort out a disapproved Adwords campaign is large.
In any case, if your AdWords ad has been disproved, you will first want to find out why. After you have found out the reason, you will want to make the necessary changes to your website or the ad. And thirdly, you will have to wait for the review process. You can find out more about this process and the steps to take on the AdWords website.