Laptop not booting properly

Assalamu alaikum.
Bro, I have been using win2008 in my Compaq 420 laptop almost for 4 years. Now recently 1 week ago, my laptop does not open properly. When I start ... ok ... it is opening, then when I put my password, password accepted and it shows only the arrow in the black screen but not shows the next windows desktop screen. I tried and move the arrow, the arrow moves but not come the next screen. I wait a long time but the same situation. On that time if I re-start the laptop then open properly, but the restart process does not work for all time. For this problem, I freshly reset the windows2008, but the same problem appear.
Laptop configuration : RAM- 2GB, Processor- Intel Core 2 Duo
Now what can I do in the situation.
Pls, help me to give a good suggestion. Your cooperation will be highly appreciated.

Thanks