I don't think that can be prevented as that is set already by the installer.
I also use Revo Uninstaller. I prefer its uninstalling capabilities over CCleaner's, as CCleaner only calls for the program's own uninstaller, while Revo has deeper cleaning methods available.
A. Right after installation, to offer paid versions at a discount, or to offer the user a look at other software of the vendor, or to simply say thank you for installing.
or
B. Upon uninstallation where they offer you upgrades at discounts, and or want to ask you questions about your experience and why you are uninstalling so they can better the product.
These being built into the installers/uninstallers are not something you can stop. The only way to aviod it period is to not install or uninstall anything.