Q: bootcamp 5 and windows 7 or windows 10

Hello!

I have got some problems about using Windows 7 i recently installed in normal way i am used to. But now something has seem to be changed... i see some weird behaviors just now, for example i cannot see any updates of the Windows just only the search bar... and the download speed is soo slow... i do not understand. I have installed all support software for Windows 7 i downloaded from apple page for my version of my iMac model.

I was wondering if i am able to run the upgrade to Windows 10 from my Windows 7 (i have got BootCamp 5) i run Mac OSX Mavericks and i can have only this version 5 installed on my Mac OSX (i cannot upgrade to Yosemite or so because of my applications)

Am i able to upgrade windows 10 from Windows 7 i have already installed? In fact i have bootcamp 5 on Mac OSX? and i cannot have bootcamp 6...