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Looking the allocations on RTT for yesterday it appears to only be 455s, 458s and 707s which serve Windsor. If you click on each train it will show which stock worked that train.
Train information at Windsor & Eton Riverside all day on 19/05/2021. From Realtime Trains, an independent source of train running info for Great Britain.
Under normal times probably yes, but 450s are regularly used on the Reading line and in some weekends of engineering works they divert the Reading trains to Windsor. I would never say you won't see one coming to Windsor.