My Windsor Kniight (new in Feb) has a brinnelled head set, so I bought a new one.

I have installed and removed headsets in the past and always used a big drift punch to remove cups by hitting down on the inside of the head tube . I can't budge the cups on this aluminum frame, even using a two pound club hammer. Even tried using a pipe wrench since the headset was toast anyway. Didn't think it would work and it didn't.

Can anybody tell me if there are systematic problems that have evolved in the last 10 years? Would I expect this type of problem with any newer frame?

I'm sure I'll take it to the LBS and maybe they can get it out with the proper tools and better support on the frame, but this isn't rocket science. It comes under the heading of "don't force it, get a bigger hammer". I did and thought it was as big as I should need.

It is probably a combination of things that makes it more difficult to remove, such as the thicker and larger diameter of the aluminum head tube. As you say, it isn't rocket science to remove the cups; it still requires brute force. But the proper tool spreads the force over the entire circumference of the cup and pushes it straight out, instead of the rocking you get with a drift punch (which tends to prevent you from removing the cup).

https://www.parktool.com/product/head-cup-remover-rt-1

Use the correct tools, and they will come out.

Using a drift, you are only hitting one area of the cup, using a head cup remover like this https://www.parktool.com/product/head-cup-remover-rt-1 other brands are available, puts the pressure around the whole cup. Also, make sure you are actually hitting the cup, and the frame doesn't have a ridge in the head tube you are hitting (unlikely, but always possible)

When you have removed the current headset, when installing the new one, would make sure you use anti-seize / grease on the cups to aid removal the next time.

I've never found it a problem; I keep an eye on the cup and move the punch when the cup budges. Once it's moved, you can usually just give it a tap every 120° or so without paying too much attention.

Mind you, that's for 1" steerer headtubes... the larger the diameter, the sketchier it is without a press or proper flared punch... I've found removing large cups a bit harder without the right tools, and installing them can be kinda tricky.

proper removal tools aside, support the frame closer to the head tube and try again

This is one of the most important steps in the removal process if you find yourself needing more than light taps.

The frond of the frame is pretty light so there's a limit to the amount of energy you can put into a blow without the frame rolling with the punch, so to speak.

Stand a 1/2" thick board in a vice, and brace the lower head lug (or welded joint) against it and the cup will move. If you want to drive it straight out without buying a special tool, find a coin or disc just slightly smaller than the head tube (about 29mm, or 33mm, for 1" or 1.125" headsets respectively). File flats on opposite sides forming a "racetrack oval" so you can slip it up into the cup. Once in it'll flop and brace across the cup so you can drive the cup straight with a punch.

Buy a short piece of 3/4" copper pipe (about 1 foot) and an end cap. Make 4 equal cuts 1/3 the length of the pipe and carefully spread the cut ends. The place the end cap on the other side, place your new tool in the opposite end of the head tube where the cup is to be removed; make sure the the cut ends are spread wide enough to rub the inside of the head tube and hit the top cap side a couple/ 3 times.. I have used this numerous times and the cups just pop off..

Would seem to be a suitable sub. Can get a real one for $20USD or $5 more for a Park model.

https://www.amazon.com/Bicycle-Bike-H...t+removal+tool

If the headset cups are aluminum, using a drift punch can damage them. The Proper Tool, or homemade facsimile thereof, is much safer.

N.B. if the headset was installed without grease, the cups may have galled in the frame, making removal much more difficult. Be sure to use grease or anti-seize when you reassemble the headset.