Vista Home Premium Air version 3.7.0.2090 and latest version of the Met Office Widget installation file.
The log file is
[2013-06-27:13:52:38] Application Installer begin with version 3.7.0.2090 on Windows Vista x86
[2013-06-27:13:52:38] Commandline is: C:\Users\Peter\Downloads\DesktopWidget-1.10.air
[2013-06-27:13:52:38] Installed runtime (3.7.0.2090) located at c:\Program Files\Common Files\Adobe AIR
[2013-06-27:13:52:39] Unpackaging file:///C:/Users/Peter/Downloads/DesktopWidget-1.10.air to C:\Windows\Temp\fla3A52.tmp
[2013-06-27:13:52:40] Package signature validation failed
[2013-06-27:13:52:40] Got an unexpected fatal error while unpackaging: [ErrorEvent type="error" bubbles=false cancelable=false eventPhase=2 text="invalid package signature" errorID=5022]
[2013-06-27:13:52:43] Application Installer end with exit code 7
However many times I re download the widget app I get the same result.
The reason for the download was that the previous installation started to behave strangely downloading a lot of stuff for no apparent reason. I have Kaspersky Internet Security which is up to date and Advanced System Care. None of my security programs report any malware.
Re-installation of windows is out of the question!!!
I have tried everything on the forum with no sucess - any help gratefully recieved. Thanks