I hadn't noticed that laptops no longer have Serial ports.
Mine does!

Like Thomas said, there are plenty of USB-to-Serial adaptors on the market; eg,
I have a Belkin DockStation (Serial+Parallel+2xPS/2+4USB), a D-Link DU-H4SMK (Serial+2xPS/2+4USB), and two ATEN USB/Serial adaptors.

For the dongle (HW key) you need a real parallel port - they say it won't work on a USB/Parallel adaptor, but they're "working on it!"

Note that the modern Keil tools are 32-bit executables, and so will not run under MS-DOS.

For discussion of specific Keil issues, try the Keil site:
http://www.keil.com/discuss