I've destroyed a few PCs in my younger years by deleting important files without realising what they did.
Whoopsies.
Surprisingly though doing that taught me more about how windows works and what various things do than most other sillies


One of the most stupid things i did were onyl recently actually.....teachers wanting access to all students home folders, now luckily 3 years ago i split them into seperate years...had i not done that this could have gone very different. 250 folders, all set NOT to inherit parent permissions, i had to give the parent folder permissions for the specific security group........of course i didn't untick the "replace all child object permissions with inheritable permissions from this object"
Luckily i noticed after about 5-6 folders had applied but if had i walked off after applying that, it could have caused quite a nuisance

EDIT: also getting exchange 2010 service pack one "ready" before you click next for the install in the approved time window.....not a good idea, i clicked next by accident and the exchange server went down for about 30 minutes mid day
