Just download the zip file (bd_rem_tool.zip), double click on it, chose "Extract all files..." from the File menu, and follow the wizard's instructions. You can use any other archiver, like WinZip. This will create a folder called bd_rem_tool.
Inside it, find the program called "bd_rem_tool.exe" (or just "bd_rem_tool") and double click on it. It is very important to extract all the files from the zip archive, and not only bd_rem_tool.exe, because all the other files are needed for the disinfection. Then follow the tool's instructions.
If you have Windows Vista with User Acccess Control enabled, or if you are running as a restricted user in Windows XP, right click the "bd_rem_tool" program and choose "Run as Administrator". You will be prompted to enter credentials for an admin account.
We recommend a system reboot after the disinfection is complete, to restore full internet access.