Install over an existing installation

norad00 · Post by **norad00** » Mon Aug 06, 2007 10:19 am

Hi,

I have a need to allow end users to install over an existing installation without having to first uninstall. Before I hack up the install scripts I thought I would check if there was an easier way to do this.

Thanks

Alex_Ronquillo · Post by **Alex_Ronquillo** » Mon Aug 06, 2007 11:14 am

With IA, you can make the uninstallation process automatic. You don't need the end user to make the unistall before install.

norad00 · Post by **norad00** » Mon Aug 06, 2007 12:17 pm

Correct. However, I want to allow them to install without having to uninstall the previous version. By default, IA seems to check for existing versions and force the user to go through a removal process first. How can I prevent this.

Thanks.

Alex_Ronquillo · Post by **Alex_Ronquillo** » Mon Aug 06, 2007 12:43 pm

Remove the code for unistallation of old versions in the MSI code. For this, you are going to need at least IA Developer Edition.

norad00 · Post by **norad00** » Mon Aug 06, 2007 2:31 pm

Simpler than I first thought. Thanks for your help.

ken rentz · Post by **ken rentz** » Mon Aug 06, 2007 6:52 pm

What sorts of problems may occur if this uninstallation piece is removed? Our customer base tends to not be very computer savvy, and the uninstall step has worried more than a few of them. Our program has been able to install over older versions of itself for some time.

MLS · Post by **MLS** » Tue Aug 07, 2007 3:24 am

I would surgest you let it deinstall still you could make systems very messy otherwise.

But you can move the step into your install phase of the setup so it's transparent to the user.

Look for the IF statement that checks NEEDSUPGRADE in the prerequisites section of your msi code and move it before the apply install command.

Not tried this my self yet but I don't think there would be a problem, am sure someone will soon say

I belive this is how other installers handle it install aware is just telling you about it

Bob T Bunny · Post by **Bob T Bunny** » Tue Aug 07, 2007 4:18 am

Firstly, apologies for the long post.

I have spent about 6 hours today trying to do the same thing (see my post about companion files, any suggestions appreciated!). We want our users to only click once at the beginning, and once at the end. Having to click Next to uninstall the previous version on 20 different computers during an installation is painful, to say the least.

This morning (New Zealand time) I moved the section MLS mentioned to the Apply Install command (actually I think I moved the whole Compile If build not patch section, or something like that), and it worked very nicely.

I did try a few different ways of installing without uninstalling first, and it didn't go well. None of my non-versioned files got installed, even though they meet the file comparison requirements. I'd suggest following the "normal" way of doing it, and let it uninstall.

My only concern is if the install fails for some reason (coming across a corrupt file part way through and falls over, for example). Because the uninstall has happened successfully, the partial installation will roll back, and the computer will be left with no version installed at all!

MLS · Post by **MLS** » Tue Aug 07, 2007 4:22 am

Yeah unfortunartly thats somthing I don't think can be handled. They would have to install again from the original disks/download they recieved if the new installer is damaged in some way