[Firmware] Sansa Express 01.01.12 firmware released

I have I have tried updating the firmware of my SanDIsk Express 1GB mp3 player. I have downloaded 01.01.12a firmware, unzipped it. I have copied the system file StMp3Rec.sys into C:\WINDOWS\system32\drivers. I have press and hold Vol- button and conencted to my computer(windows XP). It asked for installing the driver. I have seleceted automatically install option. It didnt install, got a message saying that it couldnt find the installation. Please suggest me to proceed further.