Recently, I installed the QEmu for Windows XP, but I had a problem for trying to configure the TAP interface with QEmu to communicate between host os and guest os. I has read a lot of tutorials and the problem has continued despite I follow all the steps of tutorials and articles to configure the network. The problem was the QEmu didn’t start when I has put the option ” -net tap,ifname=’…’ ” and the QEmu has returned a TAP device error message. The problem was incompatibilities between XP and QEmu. The QEmu was developed to Windos 98. Then you must use the incompatibilities tools of Windows ( property -> compatibility ). Now, it is all right.

If you want the initial steps, see:

[1] http://www.h7.dion.ne.jp/~qemu-win/TapWin32-en.html
[2] http://www.mlaureano.org/guias-e-tutoriais/configuracao-de-rede-qemu-e-windows/