Yosemite completely not working

[dushkinalex]

Hello, guys! I have installed OS X Yosemite there's a few months, but yesterday, all the system broken up and nothing's working properly.

My machine:
- MacBook Aluminium Late 2008, OS X Yosemite Public Beta 3 (updated a few days ago)

What's not working:
- Finder only shows and empty window with the "Window" in header, resetting prefs, restarting, rebooting, loading in safe mode is not able to fix this.
- Mac App Store has something that seems to a bootloop (if it's applicable to an app) - I open it, and it shows me a lollipop and loads nothing, so I can't download Mavericks.
- Safari is completely dead, Chrome hangs up sometimes, but, finally, I have Firefox
- Desktop is also not available (lollipop).
- Parallels Desktop for Windows, using which I can move and rename files to try to launch them also hangs up, like MAS.
- The BootCamp partition is not showing in the startup menu.
- I can't download another file manager, because all the time those are packed in .tar.gz or .dmg-s, but Finder is not working.
- A half of all my apps is pretty... dead.

It's a very strange situation, may be the first here But please, help

 

[atvusr]

Dunno from where these strange flaws come ....

I think the best would be to make a new, clean Install of Yosemite.

Try to get the Installer from the App-Store again, backup all your data and make a clean Install then.