msn freezes when logged on

i do tech support for a friend on his computer (vista home premium x64) and msns fine when he or i log on msn on his computer but freezes when his girlfriend logs on(even though she can log on my computer fine)

what could be wrong

Is this from the same user account, or does the gf have an account of her own?

she has a user acount of her own but most of the time she just uses his user acount to login on her msn and do what ever else

hmm her msn works on her user acount but not on his user acount

due to the blue screen issue i posted in the other thread

weve used the recovery disks to factory settings(im curently reinstalling programs), he got tired of waiting, if this doesnt work its going back he says.