Could I get banned for this?

Hello,

So i have 2 accounts, i've bought two access keys and am now running the 2 instances of the game at once on my computer.
I did not mod or change the client at all, i just copied it and pasted it elsewhere and am running them at the same time using some 3rd party thing called Guild Wars ML-X

Can I get banned for this?

I dont know ML-X, but when its purpose is to run 2 clients at the same time, i dont think there is anything to worry about (i think many players run 2 clients at the same time; mostly just to trade with themselves as playing on 2 clients is hard).

This generates revenue for Anet. Lots of people run multiple clients on the same IP. I would be more concerned about the program you are using being a key logger. Make sure it is legit.

if you were using them to farm codex afk it would be an issue, but of your just trading between them or running one on the other, i cant see it would be an issue

Guild Wars ML is a multi launcher. I've been using it for over a years, never had any problems.

Multiple Gw launchers are okay no one has ever gotten into trouble with it.

Ive used the multi launch program for a while now and no problems but i always follow a few golden rules.
1. I talk to my guildies on both accounts
2. I make sure when in outposts i dont act like bots and follow same paths
3. I talk in outposts etc on both accounts.

I do those to ensure i dont get mistaken for a bot even tho in the past players would auto assume that a 55 monk is a bot - untill you talk to them.If anything did make an alert on anets bot radar they would see from logs that both accounts talk and do random stuff - i dont think a bot would get as lost as i do at times when going places ( must ask santa for a gw sat nav ).
Anet has in the past stated the multi clients and texmod are fine if they dont alter any of the game code but anet will not offer any support on the programs.

It depends what you're doing with it... 90% of players are using multi launch to abuse dead pvp formats or just to double rewards in PvE....

As people are still abusing this 2 years after, i guess you won't get banned for it but well, you know Murphy laws...

I disagree that 90% is using multilaunch for dead pvp rewards. I think the number one reason is storage:

Buying one xunlaipane: 8,99 USD (ingame shop)
Buying another account with one campaign: 12,89 USD (two xunlaipanes + one material panel).

So I think 95% is using a second account for storage

Hmm 90% is way too high , i dont do pvp ( infact im known in my alliance for staying away from pvp totally ).
As for pve - when i do use 2 accounts at once its either as my own leech or to transfer stuff between accounts ( all hail the god of hoarding :P ) - or if the mood hits me i do lux vq for faction , sometimes controlling 2 chrs at same time isnt viable.
Btw when i do snowmen i find i get more drops being solo than having my leech with me.

My brother and I each hold an account on 2 separate PC's inside our home same ISP. No you cannot get banned what-so-ever. We've been playing together for years. Back when we first started we shared a PC and used 2 different folders.