Automatic program update and Windows 7

Question

We have a suite of programs that check for new versions at startup, and then download new versions to run if required. This is obviously a problem in Windows 7, when it is locked down as a 'standard user', as they can't write to the c:\program files directory and below. Anyone seen a example of an application that gets around with issue ?

Our applications are written in Delphi, but an example in any language would be useful.

Thanks in advance

Update:

We already have a system for determing whether a new version exists, the only problem is the download and install (if required), as this requires elevation. I can't think of a way that doesn't require an elevation prompt, or our users to reduce their security settings.

Update 2 :

I've asked a subsequent question, rather than adding a new one here

Answer 1

There are two options for application installation:

1. Application is available for all users: installation or update requires elevation for Windows Vista and up
2. The application is available for one user: install or update the application in the user profile in %LOCALAPPDATA%, no elevation is required

Ad 2: Google Chrome does this. It installs the .exe here:

%LOCALAPPDATA%\Google\Chrome\Application\chrome.exe

--jeroen

Answer 2

Typically what you will see an application do if it needs to escalate permissions is something like this.

1. Application determines if upgrade is needed
2. Application launches an "updater" service that requires "Administrator" permissions
3. Application updates itself with this updated
4. Application re-starts

This is a pretty common scenario, especially since to update your own DLL you need to go to a secondary process anyway.