dual boot keyboard stops working for login

[aiden707]

hi just installed ubuntu on acer aspire 5310 laptop, dual boot so vista on seperate partion which works fine. installed ubuntu with no problem but after choseing to load ubuntu in grub loader keyboard and mouse stop working so i cant login!!! tryed loading in ubuntu recovery mode keyboard works fine so choose normal boot and when login arives keyboard and mouse stop working. tryed with second external keyboard same problem.
still new to linux please help
thanks