step 1: open system properties(by right clicking my computer), choose tab advanced, click to environment variables button. in system variables section, click new. type this information to each textbox.
variable name: moz_no_remote(should be all small letter)
variable value: 1
press ok to close all windows

step 2: open firefox icon’s properties(from desktop and quick launch). add extension -p to command line(like “c:program filesmozilla firefoxfirefox.exe” -p). press ok.
done!!!!!!!!!!!
while starting firefox u have to create two separate profiles of firefox so that u can login to two accounts of any(orkut,yahoo,rediff or anything else)……. for three logins create three profiles of firefox………