It's not just the user/group/other bits that you list that are important, but also what user/group is actually set on the files as well as as what user/group the httpd is runnign at (that's configurable in apache's httpd.conf)
Windows doesn;t ahve a clue when it comes to unix permissions.
That clue has to come from the transfer program. I'd guess it's a ftp client? It needs to be configured, or the user needs to be taught to set the right permissions manually.
On a unix machine it's pretty easy to set permissions (even automated).
but if you run that from the httpd server it's likely it'll already needs more permissions that it's got if the user messes up things.
Now properly coded your PHP application should catch the error that it cannot write to the files it needs to write to.