Run the H2TestW (after wiping the card) and it’ll confirm both the actual capacity, as well as the write speed.
Then run the official SD Formatter, as it will format the card correctly and will enable the full speed (can make a huge difference compared to the standard windows format tool, I’ve seen a 10mb/sec difference with it).
Try H2TestW again after using the formatter. Compare the difference.
After formatting them correctly, try them in your Canon (make sure the H2TestW temporary files are gone from the card).
In my recent attempts to set up my windows 7 netbook with an windows XP partition, I stumbled across the following interesting article on using a virtual pc to achieve what I was after.
Windows 7 Virtual PC and Windows XP Mode Official Direct Download Links
Download KB977206 to Run Windows Virtual PC (XP Mode or VM) With No Hardware Virtualization
Seems like a less painful way of achieving my goal !!!
For tips on windows virtual pc, try: