fed up of blue screen:(

[Henry Blewer]

Your Granddad is right. Touch the bottom aluminum of the case before doing anything. That will ground the static.

[jaf]

my granddad is an electrical engineer he says those wrist straps are useless

Are you sure he's not talking about wireless or dissipative wrist straps?  I've been away from micro-miniature repair for a few years, but you couldn't get into our facility without using ESD equipment.  And if you can work with one hand (try replacing a CPU fan) then holding the case will work.

[Henry Blewer]

A mat on the floor which is grounded works much better. It's more expensive and can be hard to set up. But we had this in the computer shop I worked at. When I got my certification from Commodore back in the late 1980's, they recommended this. Commodore in many ways was a messed up company. The techs who worked there were pretty smart. In many ways their computers outclassed other computers in that era. Many of the technologies they implemented still influence computer design to this day.

[jaf]

Yes, EST mats and many other devices are needed, depending the type of equipment you work on.  I think for general, at home pc service, a wrist strap is a safe way to go, but there will always be the "I've never used one and never had a problem..."  A lot depends on the type of flooring and even the atmospheric environment.

[Henry Blewer]

True. I use extreme caution in winter. Static seems to be more prevalent during that time.

[Dune]

Would a length of copper/ironwire attached to wrist and pc case be good enough?

[Henry Blewer]

The wrist grounding gizmo has an advantage. It does not come off easily. The mat can't fall off, unless you turn off gravity.

Personally, I have always used touching the aluminum part of the case when I work on my machine. I have never had a problem. I would prefer the mat.