You do not require a particular web browser to connect to MS ftp site, just make sure the browser [or ftp client] you're using sends automatically an email address [any, even fake] to their servers per request.
I usually use Netscape Navigator 3.04 [very old, dates back to 1997
] or WS_FTP LE to access public ftp servers.
Passive mode [also available as an option in most FTP clients] only makes your broadband [xDSL/cable/sattelite/LAN] connection more compatible with any ftp server, which doesn't necessarily have to be the MS one.
PASV [RFC 959]:
This command requests the server to "listen" on a data port (which is not its default data port) and to wait for a connection rather than initiate one upon receipt of a transfer command. The response to this command includes the host and port address this server is listening on.
Bassically the ftp control port is 20 [and the data port is 21]. When you connect to an ftp server, the server starts sending the PASV command back to your computer, to check your IP, 'cuz all access [as you may already know] is logged on most servers.
If your computer sends back a data packet [reply], that means you're ok and will let you connect.
But if your upstream [outgoing] packets are blocked by protocol restrictions [RE: FTP active mode] by a firewall, monitoring software, OS restrictions etc, then the ftp server you're trying to connect to will refuse your request and boot you out.
So it's recommended to enable FTP passive mode to be able to connect by sending a [fake] email address [most browsers + ftp clients have this option], which is the minimum requirement to get on most FTP servers that are open to the public.
MS ftp servers are annoying because they send the PASV command periodically [quite often], so if you are connected to their server but you're not actively browsing or downloading something after a couple of minutes, you're treated as a new customer, and they'll send a new PASV command all over again.
The bad news is that the Win98 Resource Kit (RK) ftp server will be shut down by MS in May 2005
So go ahead and download while you can.