Wireless network card..

When you've upgraded the wireless adapter might actually work better, due to better hardware support provided by windows 7.

I've used usb wireless adapters for years, and had best results when combining wireless routers with usb adapters of the same brands. My best results were with brands like Sitecom (fairly cheap) and Thomson (kind of expensive - specially the usb adapters - but very stable in my experience).

As for your memory question, I will leave that to someone with more RAM knowledge.

hi there :)
tp-link i swear by for wireless usb/pci cards. the pci card is 100% better than usb in my opinion and experience. here are my top pci and usb adapters.

Adapter TL-WN822N 300Mbps High Gain Wireless USB >>> Welcome to TP-LINK

What This Product Does
The TL-WN822N High Gain USB Adapter is a 300Mbps wireless client, which allows users to connect a desktop or notebook computer to a wireless network and access a high-speed Internet connection. It is fully interoperable with IEEE 802.11 b/g/n wireless devices, delivering speedy 11n speeds and reliable signal for lag-free online gaming, Internet calls or even HD video streaming.

TL-WN951N 300Mbps Wireless N PCI Adapter >>> Welcome to TP-LINK

What This Product Does

Wireless N PCI Adapter TL-WN951N allows you to connect a desktop computer to a wireless network and access high-speed Internet connection. Comply with IEEE 802.11n, they provide wireless speed up to 300Mbps, which is beneficial for the online gaming or even HD video streaming.

the Kingston memory is a good choice reliable and well built most memory modules are at a good price this year across the world. Its advisable to buy the same type by the same manufacturer best not mix and match. here is a good program for seeing details of your ram called rammon LINK >>> PassMark RAMMon - Identify RAM type, speed & memory timings (IF YOU DECIDE TO DOWNLOAD MAKE SURE YOU CHOOSE THE 64 BIT VERSION FOR YOUR MACHINE)

RAMMon is an easy to use Windows based application that allows users to quickly retrieve the Serial Presence Detect (SPD) data from their RAM modules. It will allow users to identify a multitude of attributes, of which, includes the manufacturer, the clockspeed and other data of their DDR2, DDR3, XMP and EPP memory devices and even some older memory types. It uses SysInfo DLL SDK to gather the SPD attributes from RAM devices. This information provides a snapshot of the available data for each RAM module installed on the system.