My question about the reconfiguration delay when switching between Access 2003 and 2007 the comment was made:
Btw, you can't avoid the reconfiguration between Access 2007 and earlier versions. Access 2007 uses some of the same registry keys as earlier versions and they have to be rewritten when opening Access 2007.
If this is so then is it actually safe to be running/developing databases in both versions at the same time? Do the registry changes affect the operation of Access once it has started up. For example recompiling/saving changes to objects?
It works most of the time but it's not perfectly safe, which is why Microsft refuses to support multiple installations of Microsoft Office on the same pc. The recommended solution is to install a virtual machine and install the second Microsoft Office version on the virtual machine. Then you can switch from one version of Access to the other without them interfering with one another (and no switching time wait!)
Microsoft offers a free download of Virtual PC 2007 in both 32 bit and 64 bit versions:
Here's the service pack: