Sibelius 7.5 installation issue Win 8

[szawadzkipiano]

Hello.
Today I have purchased Sibelius 7.5. I have a notebook with Windows 8.
I have just tried to install Sibelius on my computer, but it doesn't work!
When I open Sibelius751Installer ( as a administrator)
first it opnes a window "
Sibelius 7.5 Setup is preparing the InstallShield Wizard (....)
"Installing Avid Sibelius x64"

But when this green line of "Installing Avid Sibelius x64" comes to the end, this window freezes .

In the meantime installation begins, I select langauge.

During the installation (when in center I see big SIBELIUS 7.5 screen, and on the right corner I see "Sibelius 7.5 InstallShield Wizard"
I get a message:
"Unable to save file:
C:/Users/Sebastian/AppData/Local/DownloadedInstallations/(3B80D50E-BB35-48C*-AD06-93569E7.5.msi
This process has no acces to this file, becasuse is used by another process"

And it ask me for another localization for installation files.
I click another localization.

Then I see:
-Welcome to the InstallShield Wizard for Sibelius 7.5
I clik next
-License agreement - next
-Destination folder - next
- Select Start Menu folder -next
- Ready to install - next

AND THEN INSTALLATION COMPLETELY DISAPPEAR! and I see only this frozen window, which I mentioned before ,
"Sibelius 7.5 Setup is preparing the InstallShield Wizard (....)
"Installing Avid Sibelius x64"

PLEASE, help me! I need to start to work with my music today, but I spent whole day just on trying to install this program.....

[bobp]

There is an issue with W8 and Sib 7.5 having to do with dpi scaling. Somewhere in screen settings ( I forget where, do a search) you can change font resolution (dpi). Default may be 200%. If so, try 150%. This issue can cause all kinds of problems from not installing, to not loading, to not running.