My answer to him was YES - it can be done. I performed the following demonstration to him:
I reverted my thinapp capture WinXP system to the clean state snapshot. Once reverted, I went to microsoft.com and downloaded the IE8 setup to the capture system:
I then started the ThinApp capture and let it do its pre-setup Scan. Once the scan was done, I minimized the ThinApp Capture and kicked off the IE8 install:
Internet Explorer setup went without a hitch. Once it completed, it asked for a reboot... No worries there. ThinApp handles a situation like that without a problem. You just need to let the setup reboot the system. Once the system comes back up, the ThinApp Capture will start automatically and give you the choice to continue:
I asked it to continue the installation process. Once it performed its post-setup scan I told it to make IE8 available to all Domain Users:
Afterwards, it completed the build process and I copied the package (I called it Internet Explorer.exe) to a network location. I asked my test user to run it from their typical desktop (with IE6 only). They could run IE8 without any issues. Also, running IE8 alongside IE6 was without any problems:
The screenshot below demonstrates how IE6 and IE8 are run alongside on the Adobe Flash website. Note: IE8 has Flash installed, and IE6 does not have the Flash plug-in installed:
This further demonstrates application management power and flexibility that comes with ThinApp.