Will changing the format of my videos make the quality suffer?

I'm getting a canon rebel t2i in a couple weeks and i read that all the videos appear as "mov." files once uploaded to the computer. "Mov." files are very compatible with macs, but i'm still saving up for a mac. so, to use the videos on my editing software on windows, i have to convert everything to "wmv." files. Will doing this effect the quality of the video?