Wow... That could be a contender for worst post ever!
- Posted in the wrong section (I'm moving it to "Windows Hosts").
- Wrong (non-existant) VBox version number given.
- No explicit mention of host OS (mention of Win7 could mean the guest, profile says "Ubuntu other").
- An error message is quoted, but I suspect the wording given is completely wrong and should be "Failed to install NTCreateSection monitor".
- The topic title is equally wrong and "net" will attract the wrong helpers.
- No logs.
And all that in just a few lines.
Fun aside, I still recognize the problem. You need to downgrade to 4.3.12 and await a future VBox release. Please, and mostly for your own sake, in future try to be more precise when reporting problems! I only stood a chance this time because the question is a FAQ.