I have seen this on a large business network, a user opened a malicious email and got infected. It will spread to mapped drives so it spread to their server and encrypted their sales program's database files. Luckily we had shadow copies and full backups to restore or they would have been in deep.
You're hard pressed to find a good free Cloud backup solution. If you are doing file backups, Dropbox is not bad, but limited with space if you are just using free. If you want an image of your machine, Macrium Reflect free version works well. Also have a look at Comodo backup.
This will most likely have to do with host records in your account that hosts your domain. Either "A" records or CN, cant remember off the top of my head.
Yes we use this at a couple of our schools. That and Barracuda are the most popular brands. I think I prefer Barracuda though. Very helpful in blocking anything, multiple ways to set it up by policies etc. Detailed statistics on websites blocked. Some even show bandwidth usage etc.
I ran into a problem similar to this. I could not access a share from another machine. I had to add the account of the computer trying to access the share to the computer that is sharing the folder. Same username as password. OR you can map it as a network drive and check then "Login with...
Normally when I have this issue with wireless adapters I go into device manager and uninstall the wireless card. Reboot the computer, it will reinstall and most problems are solved.