It is NOT possible for the Portable version to give you this same problem,
because there is no Google Chrome offer to be declined.
Your crash may be due to a Windows Registry error that has made inaccessible the key which determines whether you have recently declined the Chrome offer.
OK, here is what i would try. Just me. I don't see how it could cause harm, but someone else may jump in and say differently.
I would uninstall Defraggler. Restart twice. Install Ccleaner. Use Ccleaner to look for any leftovers from the now uninstalled Defraggler. Use the CCleaner registry checker to look for leftovers. Be careful, back up any registry deletions to a folder you can remember.
Restart. Reinstall Defraggler.
The first installation of Defraggler may have made a small change in the registry. The new installation of defraggler might hang when it gets to that. Maybe Ccleaner will remove it.
Fwiw, the piriform developers do read all these threads, but they stay busy writing code, and usually don't comment.
From what I've noticed Google offers in software are stored within the softwares very own registry area, i.e. under; Adobe, Piriform, etc., therefore what kroozer stated to do with an uninstall should effectively remove any possible corrupt Google key.
Also keep in mind some anti-virus can give grief with installers that bundle things like Google offers, etc., which is why Hazelnut's recommendation to install it Safe Mode could be a possible solution.