Signs that you have outgrown your custom-built MS Access application slow performance with more users, more features, more data, poor reliability, and issues with data integrity. MSDE is Microsoft's starter version of its SQL Server product line. MSDE is a fully functional SQL Server, with licensing restrictions (you cannot expose MSDE to the Internet) , and a few performance limitations imposed by the operating system. MSDE is the intermediate step between the MS Access native Jet Engine and MS SQL Server, and can be used on LANs or standalone on laptops and PCs. If you need help upsizing to MSDE, or need help understanding how MSDE works, PCA can help you. With appropriate licensing, you can even create a distributed database MSDE application.

MS Access has several inherent technical limitations. Expect to run into problems (slow performance, corrupt database, application crashes, etc.) if your MS application goes into the "Caution" or the "Stop" zones for any one of the criteria below:

MS Access, MSDE and MS SQL Server provide different capabilities, and the following will help you decide which one is the best suited to your business needs:

MS Access connected to an MSDE database also has limitations. You cannot for example use MSDE if your database is exposed to the Internet thru anything other than MS Access or Active Server Pages (.ASP). If this is the case, you must purchase (or already own) a SQL Server License from Microsoft. This is purely a Microsoft Licensing issue — MSDE and MS SQL Server are the same database engine

In addition, MSDE has a built-in "performance governor" on Process Queues that limit the number of simultaneous End Users to 8 concurrent (active) sessions. Access MSDE is also slightly more difficult to develop custom business applications on, and more difficult/expensive to install and configure vs. MS SQL Server. If supporting a dozen or more end users over the Internet is a requirement, then MS SQL Server (not MSDE) is the right choice.