Garmin Express 7.2.1.0 does not install correctly.

Same here. I see there are others with a similar problem. It demands that I log in and then fails to recognize me. I'll wait and see if Garmin are aware and fix it, otherwise I'll have to remove it and try what you did.

Ho riscontrato problemi anch'io... Ho disinstallato e reinstallato la versione 7.1.3.0 e, solo ora, tutto funziona nuovamente. Spero si possa rimanere con questa versione.

I moved from GE 7.1.4.0 to 7.2.1.0 on a 64 bit running 20H2 without hitting any problems.  Takes around 1 minute for computer and fully charged satnav (DriveSmart LMT-D) to recognise and connect.  I appreciate it doesn't help you sort your problem but wanted to let you know that it does work.  Hope you find a solution.

Mine all connect too.

HI, got two Forerunner410 and since i installed 7.2.1.0, unable to sync or reinstall both watch. how did you get previous version of Express?

I cannot emphasise enough that I am NOT a computer 'whizzkid'.  My first satnav was a 760T which must be around 10 years ago, I should think.  Ever since then, following my initial GE installation, I have always used the screen pop-up advising me that an update is available.  I have not used any other method.  As stated previously, I went direct from 7.1.4.0 to 7.2.1.0 having missed the one in between.  I believe it was only available for a very short time before the latter was issued. I have never gone back (not needed to) to an earlier version of GE. I sometimes wonder when I see the problems people have that maybe they are caused by having more than one device using GE. I have never had more than a single satnav linked.  Being very ignorant about the workings of computers/Windows I always accept the default or recommended settings to software and never change any locations or anything like that.  I hope someone more technical than me can help solve your problem.

I have 6 devices connected via Express and it's always worked, so while you have just one device I have many.  Like you though I tend to accept default installs and keep Windows up to date.