If you try to install the new Google Photos Screensaver on Vista, through the Google Updater, you’ll probably run into the following error:
The installer has encountered an unexpected error installing this package. This may indicate a problem with this package. The error code is 2739.
This is an MSI error that means Javascript is not registered on the machine. You can fix this by registering jscript.dll from a command prompt (with administrator rights)as follows:
c:\windows\system32>regsvr32 jscript.dll
Once you’ve done this, run Google Updater again to reinstall the Google Photos Screensaver, and it will work.
The new version of the screensaver is pretty sweet — it now supports local Picasa albums, Picasa Web albums, and photo RSS feeds.