sync android calendar (tasks) with calendar from PC
As you're after a plain Android &lt;-> Windows solution, apart from different hosted solutions, MyPhoneExplorer might also be worth consideration. AFAIK it can sync your Android calender with different Windows solutions, especially Outlook, but IMHO also others. According to its description, this also includes – tada! – even your favorite Windows calendar:


  MyPhoneExplorer is a powerful phone management software for your Desktop PC. Some features:
  
  
  sync your phone with Outlook, Thunderbird, Sunbird, Lotus Notes, Tobit David, Windows Contacts, Windows Calendar,...
  manage your SMS, Calllists, Apps, Files, handle Calls, create backups...
  Connection via WiFi, USB-Cable or Bluetooth.
  
  
  This is the client which is needed for phone, you'll need also the desktop-software which can be downloaded at www.fjsoft.at.


(emphasis mine)

I think this will suit you best. MyPhoneExplorer is said to be a real good solution (as a side-effect, it even helps you with backups, and other means of managing your Android device). Not being a Windows user, I cannot speak from my own experience, though – but a Playstore-rating of 4.6 with ~20k votes should mean something, too :)