Yet Another Noob Confused By Critical Error Message

[Follicle]

Okay, I have been running a free forum over on Lefora for a few months, and recently bought a domain name in order to make my forum more legit and get past some of the limitations of Lefora(which has been a great and intuitive starter forum).

I get this message when installing SMF:

Critical Error!

You're on a windows server, and some crucial files are not writable. Please ask your host to give write permissions to the user PHP is running under for the files in your SMF installation. The following files or directories need to be writable:
•agreement.txt
•Settings.php
•Settings_bak.php


Looking around a bit in these forums, I see that the solution to this for Windows XP(I am using service pack 3) is to go to My Computer>Tools>Folder Options>View, then uncheck "Simple File Sharing(Recommended)". Problem is, no such check box is on that list. So I am stymied.

Also, when I buy a new computer, will I be able to transfer my SMF files to it without losing forum archives, or would I basically be starting over at that point?

Please help! Thanks...