I'm using Nokia C2-03 from a month
When I tried to connect internet on my PC using Nokia PC suite it showing a message "There's a problem with connecting to TATADOCOMO"
Even I tried with manual settings but no use
While using on mobile it connects well
Please elaborate, because to my understanding, you are having trouble connecting your PC to the internet using what means? Either a router, LAN connection or through you phone?
If it is through router, try to reset the router. But if you are using the phone as a modem, make sure you have requested all the settings from your operator. IF this still does not allow you to connect, do a soft reset on your device which will reset your settings. To do this, enter *#7780# into you keypad and when prompted, enter 12345.
Hope this helps.