How do I upsize from Access to SQL Server?

Access is not truly meant for concurrent use. Microsoft made it easy to use Access over the web so that small companies who couldn't afford (or were intimidated by) SQL Server would have some database platform to use for their LANs (great way to sell more copies of the higher-end Office package, as well). Unfortunately for Internet developers, Access does not handle more than a handful of simultaneous users very well at all. So if you've got a family site that only your friends and such are looking at, Access is probably fine. For anything more than that, you'll probably want to use SQL Server. 
 
Here are two KB articles and a white paper that will help you upsize your Access database to SQL Server (6.5 or greater): 
 
    KB #237980  How to Convert an Access Database to SQL Server 
 
    KB #325017  HOW TO: Use the Microsoft Access Upsizing Wizard 
 
    KB #330468 HOW TO: Use the Microsoft Access 2002 Upsizing Wizard 
 
    KB #294407  "Access 2002 Upsizing Tools" White Paper 
 
Also see this page: 
 
    SQL Server and Microsoft Access 
 
If you know you are converting from Access 2000 to SQL Server 2000, you may want to pick up the SQL Server 2000 Resource Kit. It has an updated version of the upsizing wizard that fixes some problems, and makes Access 2000 projects (.adp) much more fluent in the changes to SQL Server 2000. 
 
Also, the book "Microsoft Access Developer's Guide to SQ..." by Andy Baron and Mary Chipman covers the upsizing process fairly well. 
 
Russell Sinclair's "From Access to SQL Server" will certainly help with the migration process, and understanding the differences between the two platforms. For a brief summary of the differences between Access and SQL Server, see Article #2214. 
 
There are also some 3rd party products out there that may help in your migration: 
 
    Access-to-MSSQL 
 
    Converter Technology 
 
    DataJunction djCosmos 
 
    Database Converter 
 
    dbPal 
 
    SSW Upsizing Pro 
 
Finally, here are some Knowledge Base articles you may want to glance over before proceeding: 
 
    KB #328319  Issues with the Access 2002 Upsizing Wizard 
 
    KB #325019  Issues with the Access 2000 Upsizing Wizard 
 
    KB #288300  "Microsoft Access Can't Find the Wizard..." Error [...] 
 
    KB #282380  Bad File Name or Number [...] 
 
    KB #281950  Database Unexpectedly Upsized [...] 
 
    KB #272384  "Overflow" Error Message When You Try [...] 
 
    KB #269824  Incompatibility Issues Between Access 2000 Projects [...] 
 
    KB #165827  "Overflow" or "Division by Zero" Error Upsizing Table 
 
    KB #153034  Table Is Not Exported Using the Upsizing Tools 
 
Now that you see how much work is involved, and that there are plenty of potential issues, wouldn't it make sense to just prototype your application using SQL Server in the first place?