If you are able to do the import again, you could go back to your Mac version, delete the scheduled transactions, and then do the export/import.
If you don't want to go through that again, I suggest you post this question in a Quicken Windows category of the site, since this category is mostly read by Mac users (like me) who just don't know the ins and outs of Quicken Windows.
Or you could call Quicken Support to see if someone there can give you a trick for deleting a scheduled transaction which says it cannot be deleted.