Upgrading PIX Firewall Firmware

I'm having difficulty upgrading my Cisco Systems Secure PIX Firewall 515 appliance to the most recent firmware version. I downloaded the Internetworking Operating System (IOS) update, but the instructions specify that I must start from a 3.5" disk. My Cisco Secure PIX Firewall 515 has a USB port but no floppy disk drive, so I'm not having much success. Do you have any suggestions? I'd also appreciate any tips about using the Cisco VPN 3000 client with Windows 2000 or Windows NT.

Sure enough, the instructions to update PIX firewalls to the most recent IOS version begin by describing the disk-drive setup. (The Cisco Secure PIX Firewall 520 has a 3.5" disk drive, but the vendor is phasing out that product.) I don't know whether you can use Cisco Secure PIX Firewall 515's USB port to attach a disk drive and then follow the directions, but I do know that you can skip this setup step altogether. Instead, proceed as follows:

The PIX supports PPTP, but the VPN 3000 client won't work in Win2K. However, Cisco is working on a new VPN client that the company claims will be available by the time you read this.