Check for a file on HDD, display dialog if file exists, halting install?

[scottdj]

Building install package using InstallShield 2008, target OSes Windows XP SP2, and Vista.

How do I:

1) Check if a particular file exists on the HDD.
2) If the file exists, popup a dialog telling user to uninstall previous version of product before running the new install program?


Another option instead of 1) would be to check for a GUID? Does each InstallShield install package have a unique GUID that I could check for, if so, where would I find it?

THX
Scott

[RobertDickau]

What type of project? If MSI, you might look into the System Search Wizard for finding existing data, and look into launch conditions to display a message and exit based on a condition.