UBUNTU upgrade over ZORIN 6.1

I built a new computer based on AMD A-10 processor and tried several Linux OSs before going with ZORIN 6.1.
I was happy with ZORIN and after several weeks of tweaking my only problem left was download speeds.
Software updater wanted to up grade to UBUNTU 12.10 and i did. [this is my first Linux computer]
It caused a lot of problems and the internet is blocked.
I ran 'update grub' as was recommended here and that solved shut down problems, but did not change wireless problems.
My question is can i load 6.2 over what i now have or must i start fresh?

My suggestion would be to start fresh. Keep in mind that zorin (even 6.2) is based on ubuntu 12.04 and not on 12.10. So you should not upgrade to 12.10.
Since you did, I do not know what packages were installed or not, so this is why if I was in your shoes, I would make a fresh install of zorin 6.2.

As regards your wireless problems, when you install zorin 6.2, open terminal and post back the results of the following commands to check if we can improve your wireless.

lspci -nn
lsusb
sudo lshw -c network
sudo rfkill list all

Thank you, what i expected.