Or repair the packing.

Or maybe just tighten the packing nut.

Tighten the packing nut. Remove the handle, tighten the packing nut at the end of the stem and reinstall the handle.

I used penetrating oil and my biggest screw driver and can’t get the screw to budge?!?

HI, I never seen a valve like that, but it looks like it may have a back flow preventer. Put the hose on with the nozzle closed and turn the water on and see if the water may be coming from the backflow preventer.

Good Luck Woodbutcher

Screw seized? Ok lets regroup and revise the plan. On second look I noticed the vacuum breaker, inspect leak closly and tell us if any water comes from beneath that cap on top while under pressure (it is suposed to leak every time faucet is turned off) . If vac breaker leaks stem packing won't help so we need to do something different.

I did finally get the handle off with a third dose of WD. The plastic packing nut was loose. I tightened it and put the handle back on but it still leaked under pressure. Perhaps the plastic nut needs replacing.

Or replace the packing as Dadoes suggested.

https://www.amazon.com/Danco-80794-Faucet-Packing-White/dp/B000FPAO2Y/ref=sr_1_2?keywords=valve+packing+rope&qid=1686752342&sr=8-2

Put a hose on and turn faucet on a little until stem begins leaking, leave water running and remove handle to expose packing nut. Slowly tightening nut should slow and eventualy stop leak. Occasionally stick handle on to move it back and forth. If handle or nut becomes difficult to turn before leak stops,shut it off and buy some teflon packing string anywhere plumbing is sold. Follow instruction on packing string. In the absence of instructions,with water off,remove handle and packing nut. Depending on string diameter,wrap it around stem 2-3 times and clip extra string off. Replace nut and snug it up. Turn water on. If leak presists,slowly tighten nut as before. That should take care of it unless leak has been neglected for months in which case wrapping additional string on stem might be required.