If you have administrator access to a Windows machine, you should strongly consider loading the kqemu accelerator. With this, the efficiency of QEMU improves dramatically.
To do this, go to http://www.nongnu.org/qemu/kqemu-1.4.0pre1.tar.gz, and unzip the file. You will need 7-zip (http://7-zip.org) to do this. Hint: install 7-zip on your thumb drive or external hard disk drive, as you will find it quite useful.
Once unzipped to a folder, you should find kqemu.inf in the top level unzipped folder. Right-click and select “install” to complete the installation.