You can always upgrade to 64bit, but that require wiping out all of your data so make sure to backup everything on your comp before you proceed (if you do).
Certain processors are incapable of running 64 bit windows. I have a couple of old Samsungs that won't do it.
You should be able to interact with a Ledger through Electrum which should run on a 32 bit machine -
https://support.ledgerwallet.com/hc/en-us/articles/115005161925-Set-up-and-use-ElectrumI don't know how much functionality you give up with that though.