It is indeed a must to register Crystal Reports to deploy and package things properly because you need to add a certain registration code before you can package things properly.
If you don't add that code and still deploy things you'll get some error about a keycode not being correct and won't be able to view your reports.
For complete instructions on how to package CR's check out this pdf file on the Crystal Decisions site:
crnet_deployment.pdf
Beware as well that if you've used any patches for the CR-dll's that you'll need to run those patches as well after installing your application elsewhere.
The merge modules you need for deployment (you'll read about them in the pdf-file) don't deploy the patched versions of your dll's, but instead deploy a version that's baked into the merge modules themselves, so you'll always be stuck with older dll-versions.
I've just had a whole e-mail discussion with 2 ppl from Crystal Decisions about this problem with outdated dll's getting packaged and they're looking into getting this fixed properly (i.e. having the patch also update the merge modules .... don't even think about downloading new merge modules to fix this "outdated dll's" problem, they're not available *sigh*), but I think it might be a while before it actually is.
Also, if you've installed your application plus a dll-patch and things still aren't working as they should, download the latest version of the patch and try installing that.
On pc's running just the .NET Framework instead of the entire VS.NET design environment, the older patches may be incapable of registering the new/patched dll's so that even if you think you're using the new ones you're actually still using the old ones in your installed application.
(In win2000 Pro you can easily check which version is registered by going to C:\WINNT\assembly, right-clicking on the dll you want, selecting "properties" and going to the "Version" tab and check if the version mentioned there is the same as the version of your physicall dll-file.)
And on a last note ... when installing the patch it's best to be logged in while having administrator rights (at least in win2000 Pro it is).
If you're not logged in with those rights it might be that even the newer updated patches can't register the new/patched dll's.
That in a nutshell is 2 weeks worth of testing, trial and error and almost daily communications with Crystal Decisions.
Maybe this will spare someone my recent frustrations on deploying CR's for .NET.