Slackware comes with drivers for most hardware. For the most part it will detect and install the correct kernel modules ( drivers ).
You need to learn a few commands to display what hardware you have. Open a command prompt, called a konsole in KDE. Run the command '/sbin/lspci' ( without the quotes ). This will print a list of the major hardware installed on the system board.
If a particular device is not working, look through the list for the item. Cut and paste the line(s) into the thread you post looking for help. This info is how we find the kernel module ( driver ) you will need.
Things that cause the most problems for noobs are the graphics modules for Nvidia and ATI chip sets, some audio cards, and wireless.
Almost anything else will work out of the box. Nvidia and ATI modules are available from the manufacturers. If you look in the Slackware forum on this board, you will find a sticky thread at the top of the page telling you how to install proprietary drivers.
Audio cards, I go to this link -->
http://www.alsa-project.org/main/index.php/Main_Page for audio driver information.
External devices ( printers scanners usb devices ) are a little different. For any usb device, start with a 'lsusb' command. That will list the connected devices on your USB bus. I usually Google for the driver. For printers go to linuxprinting.org, and scanners
http://www.sane-project.org/ is the link.
Linuxprinting also lists drivers for multifunction devices; if they are available. Of course it is best to research your hardware before you install.
You should be able to find out what hardware you have by either looking in the device manager in windows, or using the above commands in your virtual machine.
Hope this helps.