If you upgrade to 64-Bit OS in WINDOWS 7 or WINDOWS VISTA, then one ESSENTIAL DRIVER you will likely miss is your Wi-Fi card...and then will have to shop for new 64Bit WiFi device bec Linksys, Belkin, NetGear all do not offer 64 bit WiFi drivers on their websites rather they want you to buy a new one.I know we have superfast Dell Studio XPS 435 Mini-Tower with Intel Pentium Core i7-920 CPU and 6GB DDR3 memory upgradeable to whopping 12GB that came installed with 64Bit VISTA OS. Recently we had problem with internet connections and only WiFi was working on 3 Dell Notebook PCs (Latitude D800, Latitude D 620 and Inspiron E1505) so we can backup WiFi devices when we vacation and I decided to hookup & install Linksys WUSB300N USB adapter to Dell Studio XPS 435MT desktop and found out it would not work or install the painful way...so my research resulted in buying Linksys WUSB600N dual band WiFi USB adapter that does have 64-Bit drivers and it works on both 32-Bit and 64-Bit OS,To my eyes and needs, Windows 7 is just a fix to Windows VISTA and the door to 64Bit OS bec if you didn't know your Dell D510 motherboard and 32 Bit Windows XP cannot support more than 3.5GB memory.Hope the Above Info Helps!