Access to Slough/Bucks Grammar schools from a Windsor

[Sooverit1001]

Hi all. Soon to be single parent living in zone 2 London with a DS aged 5 in Reception at a pre-prep. He is academically working beyond his expected level and the plan was for him to do 7+ exams originally. For various reasons, I am now looking to move with Ds to a grammar school access area,with easy access to the City and north (to visit family). Have always preferred areas west of London so Windsor seems a good bet in terms of affordability though the state schools are not great (so I understand). Would I still be able to access the state grammars in Slough/Bucks and maybe Reading if living in say SL4? Plan would be send him to a local prep (hopefully with financial assistance) in meantime. Thank you!

Eton is not my cup of tea either though a good school 😄
lots of food for thought here, thank you.

You would have no chance of getting a Bucks grammar from Windsor now - a few years ago, yes, and there may still be a few siblings or people who have gained a place & moved away, not coach loads though.
The Slough schools have varying admissions criteria so you would have to look at each one.

I was thinking of Burnham, Langley and at. Bernard’s grammar schools which are in bucks as in slough

Burnham is in Bucks (just) but parts of Slough are in catchment, it's the Bucks 11 plus exam. Langley & St Bernard's (Catholic school) are in Slough, so a different exam. You wouldn't get Burnham from Windsor now, you might get Langley or St Bernard's, I don't know how they work but you could easily find out.
Of course all of this assumes qualifying in the 11 plus, you would need to make sure you were happy with the non 11 plus schools in case your children didn't qualify.

Why not Reading itself? Great train access to London, pretty diverse, perfectly possible to live there without a car.

Reading School catchment area: www.reading-school.co.uk/attachments/download.asp?file=2530

But it's pretty challenging to get in.

We love living in Windsor - the castle, the river, the long walk, and the lovely community. There is school bus to St Bernard’s Grammar and we have local friends who attend. Certainly a lot of children sit the 11+ and go to the Slough/Langley grammars.