login screen hang up

[amitch88]

when i starts ubuntu the login screen does not response. mean that i can not write any thing in username field of can not use mouse. i can login in command mode but cannot login in GUI mode. Plz help me

[QIII]

Can you give us some specifications on your machine?

Make, model, graphics chipset, processor, memory ...

As much as you can would be best.

[amitch88]

i am using Dell inspiron 1545 laptop.
with 2 gb ram,
250 gb hdd,
core2duo 2 ghz,

i am using ubuntu with vista for last 2 months, but yesterday when i started ubuntu with KDE and i was going to open ntfs drive in dolphin file manager. but at that time i could not open ntfs drive so i started shell and used mount command. and then i restarted my laptop and i couldn't login.