As Xara hasn't bothered to inform on TG.

Under the Update Service, you can download Xara Web Designer and Xara Web Designer Premium here: https://www.xara.com/uk/web-designer/download/.
You can use the same download as a Trial; trials can be extended to 30 days. I usually download XDPX for a trial than XWDP for another trial and get 60 days to e really sure.

Doing this does not overwrite your version 15.m or 16.n so do not delete them.
You should be able to run up to two installations of each version so Magix has mucked around and so your install might complain you have too many installs. So complain back to Magix. Please.

As this is a fresh install, all your settings in your earlier install will not have transferred over. Tell Xara how naff this is.

Remember to use Download All in the Local Designs gallery if you are unable to copy across form your existing Cache folder.

Do not use the marketing link Magix provides:

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This forces you to think you need to pay for the update. Wrong. If you are under the Update Service cover, it is FREE. Again tell Magix and tell Xara what you think.

As it is a new version at 17.0 you might think it will have lots of new stuff. No. Xara admits it is "marketing" for Magix and Xara (MagiXara); for the rest of the Universe it is a PITA.
If you do intend to renew the Update Service use the trial period(s) mentioned above until you see v17.1 appearing. This means your eventual "fall back" should be to a version that has some of v17.0's bugs corrected.

Come back to this Thread and ask any questions to assist you getting what you have paid for.

Acorn

P.S. I do not have XWDPv17.0 as I stopped my Update Service at v15.0.
I do have v17.0 for Xara Designer Pro X.