I have a stalker that has not only taken control of my computer but is throwing lan parties...

Hello, first it's a pleasure to be able to help you today.

My name is welcome to the community.

Hello, cases like this are very unusual, for this to happen the attacker would have to have installed something on your machine, or have clicked on some program that would give access to your PC.

Ideally in these cases is to reinstall your entire operating system, and request some specialized technical help to prevent this from happening again.

Never really had the pleasure of participating in LAN parties with xbox. Back when the first Halo came out only one of us had an xbox, so it was just splitscreen mayhem. Though we did use the computer lab for LAN gaming with Descent or Warcraft back in
high school.

For: Ktownfireman Yeah I have tried to unplug the router and modem together, but no such luck.

For:MrNightmareTM My computer has a seperate connection that works fine, its just the LAN that doesn't work, So is there a way to connect my Xbox throught the Broadband connection, not the LAN?

Randy your a nice class act . But not everyone like me has a computer or a smart phone. I still have a lan line in my house..

If you are the parent and set up your daughter's own Gamertag Account as a child account, you can set her account privileges regarding communications to "Friends only", which means, only people that are already on her friend list can hear her. Even if the
stalker should be in the same chat party, the stalker can't hear what she says, and she can't hear him.

Additionally, she can bring up the stalker's gamertag profile and block as well as mute him. That way she'll appear offline to him, and any messages he sends to her via Xbox Live will be blocked and never reach her. However, as soon as
she sends a message to him, the block is lifted!

To prevent the stalker from getting into parties in the first place, have your daughter set up a Xbox chat party to require an invitation. That way she can invite her friend, but the stalker can't join them (unless he's invited by someone else).

As long as the stalker has no means to join an online match or participate in a "peer to peer" hosted chat (like a Party on Xbox Live, Skype call, or something similar), the stalker would be unable to get your home's current IP address, so they can't initiate
the DDoS attack.

However, if the DDoS attacks continue, have your ISP log these DDoS attacks, and collect information about the stalker, and report him to the police. Also get your ISP involved, as the DDoS attack is disrupting their service for their paying customers. As
DDoS attacks are illegal in most countries, you and the ISP can then press charges.

Also talk with your daughter to not engage with the stalker in any way. If he's chatting her up on SnapChat (which I don't use, so my advice might not work), have her block his account from contacting her. Make it clear to her, that she should never give
out any information to anyone on the internet.