When you try to open a compiled database file (.accde or .mde) or a compiled project file (.ade) in the original release of Microsoft Office Access 2007, you may receive the following error message:

This database is in an unrecognized format.

The database may have been created with a later version of Microsoft Office Access than the one you are using. Upgrade your version of Microsoft Office Access to the current one, and then open this database.

This error is also described in KB article 946205.

This will occur if the compiled database or project was created on a computer that has Office 2007 service pack 1 (SP1)  installed.

While you have been able to install Office 2007 service pack 1 (SP1) to correct this issue, that is not an option for some people.  If you were unable to or chose not to install Office 2007 SP1 you now have another option.  We have released a hotfix which will allow you to open a database or project that was compiled in Office 2007 SP1.  The hotfix will update the main Access executable file (msaccess.exe) and a few other key files to a version that is slightly than what you have after installing Office 2007 SP1 but it does not include all of the changes in Office 2007 SP1.

One thing to keep in mind is after you install this hotfix, any database or project that is compiled on your computer cannot be opened on a computer that still has the original version of Access 2007 installed.

For more information about and a link where you can request the hotfix see the KB article 943249.

 

Edited 4/8 @ 7:07 to correct a link to the correct KB article.