wenn ich bei Adobe Digital Editions ein Buch herunterladen will bekomme ich diese Meldung "E_IO_cannot_open". Was mach ich falsch?

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.