I followed these steps
Close all applications.
Choose Start > Run.
In the Open text box, type regedit and then press Enter. The Registry Editor opens.
In the left pane of the Registry Editor, locate the following registry key: HKEY_CURRENT_USER\Software\Adobe\Adept
Select the Adept key.
Choose File > Export.
In the Export Registry File dialog box, select Selected Branch under Export Range. Enter a name and location for the backup registry key, and then click Save.
Right-click the Adept key and choose Delete.
In the Confirm Key Delete dialog, click OK.
Close the Registry Editor.
Open Adobe Digital Editions and reauthorize.
Check Time, Date and Timezone. On of this are cause the error.
I tried the steps you have sent but still does not work , please what to do?
it's activated... Thanx for ur assistance, after I edited the time zone..
This is good.