Mailbird needs Net Framework 4.5.2 to work. My W7 laptop will not install 4.5.2 from the usual sites. Win Update lists 4.5.2 for download but fails each time even when I use Clean Boot. My desktop PC has the same system and successfully installed both 4.5.2 and Mailbird. A registry clean did find and fix some corrupted files but had no effect on my problem. What else can I try ?