What is the operating system on the laptop? You mention both Windows 2000 and Windows 98. Also, which version of 98? If you are going to install RetailEdge as a client-only install, then you need at least Windows 98 SE which supports USB ports. If you are going to do the full install (client/server), then you need Windows XP.
In practice, we recommend Windows XP. XP is more robust than 98 SE and has better performance. If you are sticking with an older operating system, make sure you have plenty of RAM.
For more details, this page has the system requirement for RetailEdge:
http://www.retailedge.com/re_systemrequirements.php