Can I upgrade my CPU on my I 5737 to allow for upgrade to windows 11 a

Even when you could upgrade before mobile became “BGA only” parts, it usually wasn’t cost effective as the laptop has other compromises you’ll probably want to address as well, raising the cost so much it didn’t make sense with how difficult it is. If you had a junk laptop or you got the CPU for practically nothing and you could gut it without damage, sure it may work out but even then, you had to be 110% sure, and be damned sure you knew it would work and the work was worth the steps involved.