Dormiens :
But installing v3.5 wont replace v4.5 right?
No it won't. If you will want to use 4-4.5 application you need 4.5 installed. If you want to use 2-3.5 application you need 3.5 installed. I repeat you can have both installed at same time withou any conflicts.
4.5 is included in windows 8. 4.5.1 included in windows 8.1 and there is also 4.5.2 out now. You get those minor versions by simple windows update.