Uninstalling old versions - VS 2003 Setup project

Hi,

Is it possible when installing a .Net app with the All Users option set to
true (built in VS 2003 & deployed as MSI file using a standard setup project)
to automatically uninstall old versions that were installed without the All
Users option? I.e. old version installed for single user, new version for all
users.

Thanks in advance,

Pete