I followed the instructions after authorizing payment for ver 7.
Ver 6 was "check for upgrades" to 6.3 build 1835.
The procedure for UPDATE LICENSE KEY will show the NEW KEY in GREEN and the old V6 key, but never goes to FINISH and never registers the NEW KEY or installs the new software. If I go back to check for upgrades, it starts the whole process again if I choose NOW. 

I am stuck in a loop and tired of trying to fix this, because v6 works perfectly and I was hoping for a smooth upgrade to 7. So far, no luck.

Frustrated purchaser

I am trying a workaround by installing refectdfull ezecutable and hoping the new license key works. I rely on this software and am not happy that I have to figure out a solution that might render my software inoperable.

Maybe there's an issue with Macrium's activation servers at the moment?  Normally when you update your license key to a V7 key and then check for updates, the prompt to upgrade to V7 shows up right away.  Anyhow, you can download the V7 installer here: http://updates.macrium.com/reflect/v7/reflectdlfull.exe

Enter the V7 key in the download agent, and then when the installation actually runs, you'll probably be prompted for your V6 key to confirm your upgrade eligibility -- or it may find it automatically from your existing installation, I'm not sure.  Either way, you should then be good to go.  Sorry you're having trouble!

Now that I am no longer paid to troubleshoot problems for other people, the time and nervous energy involved in correcting a FAILED install using Macrium instructions is lost forever,

If you attempt to use a KEY provided in e-mail from Macrium to upgrade from V6 to v7, and like mine, this KEY fails to register after UPDATE KEY procedure, wherein you are supposed to get a FINISHED button after sucess, but never do, I suggest:

Copy and paste your existing v6 key into a notepad or equivalent on your hard drive
Copy and paste the v7 key from the e-mail onto the same page and save. Keep this on your desktop.
(Copy because numeral ONE and letter ELL and numeral 5 and later ESS are very easy to get wrong.)
Try to get to reflectdfull.exe, which is the complete installer package. I got to it when I gave up all the instructions from Macrium and did Check for updates.
When you run this, you will asked to provide BOTH keys. Since you cannot install with Reflect open, your file on your desktop comes in here.
During install, I received a message that an object tracker was being installed which requires a restart of your PC.
I never got an expicit message that all was installed, the REFLECT icon  (if you have one on desktop) does not alter, so after checking Task Manager and finding nothing going on, my next few warm reboots were frought.
I use Win 7 Pro 64, and  over two warm boots and one cold: various elements failed to load, my network (cables) did not connect, Task Manager showed that Outlook and other sw was NOT RESPONDING. Clicking on the Macrium icon did nothing at all.
After about the third (this one cold) reboot, everything seemed to settle down and Reflect even started an incremental backup, presumably to back itself up. 
All in all, an unnecessarily unpleasant experience.