System error sir,i open the recieved message,a message come on mobile'system error' then my phone hanged and after this it switched off automatically.sir please send me the solution of this problem...i will very thankful to you.

It generally hangs when u install new new softwares in it, which is sometimes not compatable with ur mobile platform.
now what u have to do is u have to format ur phone to factory settings that is the only way which is to be done in regard to make ue phone run smooth

sometime when u talk for long hours on ur cell fone , it gets heat up and ur call get automatically disconnected.
u have to reset it which is sometimes dangerous to ur cell phone, it might cause some harm to it.

There r two ways to format ur Cell Phone
1. Soft Core Format
2. Hard Core Format

1. In Soft Core Format u have to dial *#7370#    or   dial  *#7780#     this will format ur phone memory and u have to manually format ur memory card

2. In Hard Core Format ur mobile gets formatted as a tough format,     u have to keep on pressing the three buttons simultaneously(at the same time) for a long period unless u get a screen on ur phone when it asks for the region(ur country).

what u have to do: 
1. switch OFF ur mobile
2. u have to press three keys at a time
    Call Button (green key) + * key + 3  at the same time
3. now dont get ur fingers off those buttons , ask someone to switch ur mobile ON (if possible make       ur cell phone placed on some table for stability) (please dont move ur fingers off those three keys       unless u get the screen where u r asked for ur region)

once u got that screen ur cell phone is formatted

NOTE: Formatting the phone with HARD CORE FORMAT METHOD may be harmful if not done in the correct way

Pls Vote for me if this solution works for u

Thank You

Vinay Ramani
India