4atRW, you can get a special by-law to enable those owners who wish to install new windows to pay for their own windows. But as far as I am aware there is no way to make the windows of the other owners stop being common property against those owners will, so those who want new windows now will have to pay (via strata fund or levy) down the track when the remaining owners need new windows. In a four lot scheme all owners would need to agree if you want a special by-law to pass responsibility for windows to individual owners to cover all of you, and it would not be in the remaining owners best interests to do so.
Note that the special by-law would have to pass responsibility for the common property to the owner, so they are able to pay for the windows themselves, but the owner of their lot would then also be responsible for any future repairs and replacements.
To add to Jimmy’s warning above and as someone in a scheme where many things were agreed to informally in the past, without special by-laws, it can be a nightmare to untangle issues down the track. New owners who have no way of knowing about the informal arrangements (because they aren’t included in the by-laws) are quite fairly able to apply strata law to get their normal rights (such as to have windows repaired by strata) and the informal agreements can’t stand up to that.