Installing on Vista Laptop

I use Vista, no problems.
Check the system requirements and the antivirus permissions

http://musescore.org/en/download#Minimum-requirements
http://musescore.org/en/node/36041

Have you tried running the installer as administrator?

My first post to MuseScore forums, so please forgive any clumsiness in formatting etc.
When MuseScore 2 was in beta, I too tried to install it on Vista.
The installation failed without any indication of what was wrong.
Last night however, I installed MuseScore 2.0.1. successfully by changing the properties of the downloaded file before trying to run it.
These are the steps in a bit more detail.
Downloaded the file via Google Chrome as before.
In the bar at the bottom of the Chrome browser page, clicked the *Show all downloads* link.
At the top right of the page which then appeared, clicked *Open downloads folder*.
In the downloads folder, located the file *MuseScore-2.0.1.msi* and right-clicked on it.
Selected *Properties* from the drop-down menu.
Noted the security message at the bottom of the Properties window and clicked the *Unblock* button next to it.
Closed the Properties window and double-clicked on MuseScore-2.0.1.msi to start installation.
If you use a different browser you may have to adapt the procedure a bit.
Hope this is helpful.