Computer Scam

I just got a phonecall from someone who said they were from the software maintenance dept of Windows computer & would walk me through my computer to fix my problems..( I have had an error or something that tells me it needs to debug so I almost allowed them to. ) Luckily I rang my computer guru & he said no way that they get in & access your computer & hijack all the info. Other people have done it & hes had to fix their computers..+ Windows don't contact you. So if they ring don't let them do anything !