Hi, before I build my new computer I plan on removing some parts from my old one, I wanted to know if I should leave the system plugged in but switched off or unplug the system from the wall (or in my case power strip) & switched off?

Also should I connect the anti-static strap to the case (even if the PC is unplugged from the wall) or should I connect the anti-static strap to something else?

The case is made of Aluminium just incase if this makes a difference.

Anti-static straps are only really any good if the PSU is switched but the PC is off, and if that's the case there are certain jobs I wouldn't want to do. What I do is ground myself to a nearby radiator pipe, (if you can actually reach one with an anti-static strap that's ideal) the metal unpainted bit on the pipe at the bottom, then leave the PSU plugged in but turned off at the back.

I forgot to mention that my whole house is carpeted (this includes bathroom, kitchen & bedrooms), any suggestions with that in mind will be very helpful & thanked in advance?

Thanks

Then be especially careful, and don't lay components down directly on the carpet.