Software & Apps File Types What Is an ADP File? How to open, edit, & convert ADP files by Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated on June 24, 2020 File Types Design Cryptocurrency MS Office Windows Linux Google Drive Apps File Types Backup & Utilities View More Tweet Share Email A file with the ADP file extension is a Microsoft Access Project file. They hold Access project information and communicate directly with a Microsoft SQL Server database, but don't contain tables or queries like ACCDB files. While much less common, ADP files may instead be audio files used in some video games or videos downloaded from video streaming websites. ADP is also a payroll service company, but it has nothing to do with this file format. You might also see these letters used in abbreviations for unrelated technology terms like active data page and auto delivery program. How to Open an ADP File ADP files that are used with Microsoft Access can, of course, be opened with the program, too, but only if you're running a version older than Access 2013; they also don't work with SQL Server 2012 or newer. We're not aware of a media player or other tool that can open ADP files that are ripped/copied from video game discs, nor do we have a download link for a compatible video player. Videos in this format are usually downloaded from browser add-ons like Video DownloadHelper in Firefox. Something you can try if you have a video file is to rename it to have the .MP4 file extension (e.g., videofile.adp to videofile.mp4). This is only going to work if the file is actually an MP4 but was incorrectly named with .ADP during the download process. How to Convert an ADP File Just as we don't have any information on opening ADP audio or video files, we also don't know of any tools to convert them to MP3s, MP4s, or any other audio/video format. Still Can't Open the File? One big reason some files don't open in programs we think they should work with is because we're misreading the file extension. This is actually really easy to do because lots of file extensions share some of of the same letters/numbers. For example, ADD looks an awful lot like ADP but that file extension is used for Dynamic AX Developer Documentation files, something entirely unrelated to Microsoft Access. ADE and APD are are also easy to confuse for this file extension.