Mike,

By default, if an uninstall detects a locked (in-use) file, it needs a reboot to finish the uninstall process.

What you can try is the following (it's in theory, I did not test it). Write a custom uninstall that can detect a command line option (e.g. /NR stands for Never Reboot or /DNR stands for Do Not Reboot or whatever). If your installer passes this command line option to the uninstall application, set the $SB_RESTARTFLAG$ Installer Flag to 0 to avoid a reboot.

You call it with something like this from your installer:
Uninst_[PRODUCTNAME].exe /U "[UNINSTALL_LOG]" /S /DNR

Note: You can use the "Get System Info(Command Line)" function to retrieve the command line parameters and then "Handle String Operation (InStr)" function to check if the command line includes /NR or /DNR or whatever. Then use "Set Installer Flag" to disable the reboot process.

Does this help?

Friedrich