This used to do my head in until I found this little tip on Lifehacker.
Picture this: You’re consolidating your digital music collection from numerous locations to a single directory on a networked drive. To save time, you don’t want to replace existing files as these are most likely duplicates, and network transfers are often slow. Unfortunately, when Windows pops up and asks you whether you want to replace the existing file, it gives you every option you’d like apart from the most useful: “No to all”.
To tell Windows “No to all”, hold down Shift while clicking No, and it will apply to all replacements for that transaction 🙂
This will also work when Windows asks whether you want to move Read-only Files or not.