I've used Corsair XMS Platinum for about 5 years in my overclocked but reliable legacy computer, so I had no hesitation in picking Corsair memory when I needed more memory to run Windows 7 with ZoneAlarm Internet Suite and ForceField. As the computer is mostly for e-mail and web browsing, CL2 would be overkill and CL3 is fine.
Window 7 can show up memory controller weaknesses. XP Pro ran happily with the two Corsair 1 GB modules and a 500 MB Corsair XMS module in an ASUS A7N8X Deluxe motherboard; the bios was reset to the slower memory settings. However, it crashed to a hard stop error when trying to run or re-install Windows 7. Removing the XMS memory, running the CL3 memory as dual channel at 2.7 volts - recommended by the Corsair web site for the A7N8X motherboard - enabled Windows 7 to run nicely.
Be aware that Windows 7 32 bit is unlikely to recognise memory over 2GB, so this 2 x 1GB kit is likely to be all that you need, unless you're running 64 bit when Windows 7 should be able to recognise 4GB of memory.
If you have a legacy machine that takes 184 pin DDR, this kit could be just what you need if you are changing to Windows 7.