To change your default font in windows:
- find out the name of the font you want to change to by selecting the font. press S-Mouse1 and choose the font you desire.
- copy the name of this font into a buffer somewhere M-x describe-face RET RET select the face name, eg: outline-bitstream vera sans mono and M-w to copy to the kill ring
- customise the default-face M-x customize-face RET default RET edit Font Family: and yank the font name from the kill buffer C-y
- click the safe for future sessions, and then click finish.