Left 4 Dead

This is a somewhat difficult achievement as you generally have someone who will alert the witch on accident because they could not find them.

I would not suggest trying to kill them as there is a chance you could startle them while trying to kill them, and even if she doesn't hit you it will still count against the achievement.

Instead whenever you hear a witch stay on the lookout and make sure you find her before continuing on.

Once you find her make sure you can go around her, if there is no possible way to get around her then you will have to kill her, and for this reason you NEED someone to carry the shotgun. If you NEED to kill her make sure the person with the shotgun is actually skilled enough to do it without startling her. Plenty of times I've heard "Let me take on the witch" only to have to revive them and tell them that I would be taking care of the rest of the witches.

EDIT: I just looked at this guide and realized it would be helpful to add my pointers on killing the witch without startling her.

In order to kill the witch you NEED a shotgun, preferably an auto, so whenever the shotgun is available grab it even the pump. To kill her you need to get right behind her and aim at her back, right beneath her hair. When she is about half way standing just start shooting. Shoot at least 3 times, this should kill her without startling her. It should only take one shot, but just in case you don't crown her it would be better screwing the achievement up and surviving than dying at the same time.

When you are going around her I would suggest doing it one or MAYBE two people at a time as having all the people trying to get past her at once has a tendency to startle her. To be safe I would suggest only having one person at a time run past her, especially if you hear her getting angry.

If you hear a special infected I would suggest trying to kill it before going around the witch. Getting hunted/smoked/boomed right behind a witch is not a situation you want to be in.

This is actually harder than it sounds to do legit but it is possible. I actually got it because one of my team-mates was an all-out witch hunter and killed all of them without startling them. Although it can be done that way I would not suggest it, instead try to avoid them at all costs and only killing them when it is absolutely necessary.

Note: This would probably be easier on the new Crash Course Campaign as there are only 2 chapters therefore there are less witches. (I have not been able to confirm if it can be unlocked on this level so if anyone does it on Crash Course please leave a comment to confirm.)

EDIT: This does work on the Crash Course campaign if you have bought it. Thanks to I M1K3Y B I for confirming this.

EDIT: Just thought I would add. If you don't have Crash Course I would suggest doing this on either No Mercy, or Dead Air, as in the other missions she can spawn in areas with limited visibility and you may accidentally run into her and startle her. No Mercy/Dead Air both offer better vantage points when searching for the witch.

You and 3 friends should start a campaign on Easy. When Chapter 5 begins, have everyone vote to return to the game lobby. Then, begin the same campaign on Easy on Chapter 5. You can do this on any campaign, do whichever you are most comfortable on. I find that Dead Air is easiest since there are NEVER witches in the finale. Can also be used to obtain Safety First, Untouchables, Stomach Upset, Unbreakable, Akimbo Assassin and Stand Tall. Simply fulfill the requirements for each achievement.

There's the legitimate way of getting this, then there's various glitches you can use if you don't want to get it in a noble fashion.

Legit: I would recommend playing a campaign you know well, in Easy mode, with four human players. Move swiftly with full captions on and when you hear a witch crying, her music cue, or the caption, just avoid that area. Find other ways around a path with your flashlight off.

Glitch: There are several, and I'll cover them in detail.

1) Play all the way through an Easy campaign without worrying about the witches. You can startle them all you like. Dead Air is probably the best one to do it on. It doesn't matter at all if you get hit by a witch, and you can just play through without worrying about it. You have to have four human players.

Now, when you get to the finale, DO NOT open the opening saferoom door and vote to return to the lobby. Now, in 'Edit Game Settings' change it to chapter 5 (which should be the finale) and start it up again. The reason this works is because the game acknowledges the fact you've played through the whole campaign, but it says you never got incapped, never healed, and so on (so you can unlock several achievements at the same time using this). Go slowly through the finale because you have more chance of a witch spawn if you're going quickly.

I hope this helps.

You can also get the achievement if you get the instant kill headshot to the witch. Doing this does not count toward "disturbing" them. Usually the headshots are so quick, she never gets a chance to get angry.

Play versus with another control, have the other control be the infected but never spawn, the player will be the only infected to spawn in the whole campaign, I got this plus 5 other achievements at the same time! This way you don't need to worry about special infected, if a witch is right in your path, use the other control to spawn next to her this will encourage the ai survivors to shoot in that direction thus the witch being disturbed by someone else :)

For this achievement, i would strongly suggest putting it on a map that you like. So personally i put it on No Mercy at the very start (You must start it from chapter one to be rewared with the achievement.) i did it on single player with the AI's. If there is a witch in the way, try and find another way round without getting to close to the witch, but if there is no other way try and find an auto shotgun, Aim it below her hair and shoot aprox. 3 times. (Shoot the head if you are good at headshotting them.) Do not expect this achievement to be awarded you on your first go, this took me about 2 go's. One you have done it you will be one happy man! PS: If you are doing it with AI's like i did, they screw up sometimes... try to make use of them though, not on the witches, but on the normal and other special infected. Good luck guys!

I am surprised no has mentioned this, but since CRASH COURSE is a really short campaign, and if you have this DLC (I only did because I glitched open the TANK achievement from it, so I had to buy it to complete) you may only have one WITCH on the whole campaign and therefore it is simple to avoid just one.