Dear sir My desktop with intel chipset with 2.66 processor and 512MB RAM and 80GB hardisk. This computer start to restarts again and again after every 2-3 Mins.I checked with changing processor and RAM but no difference please tell me appropriate solution.I think here is problem wiht graphics card.I am writing with great hope.

can be hundreds of reasons
if you suspect graphic card , remove it and use on-board vga-output , or a different card
if any change , you know the cause

but its not necessary hardware
faulty software , drivers and virus can cause this too

Dear sir My desktop with intel chipset with 2.66 processor and 512MB RAM and 80GB hardisk. This computer start to restarts again and again after every 2-3 Mins.I checked with changing processor and RAM but no difference please tell me appropriate solution.I think here is problem wiht graphics card.I am writing with great hope.

If is graphic card, it's more likely to hear a sound from your PC when boot/restart...
Try this:
go to System Properties->Advanced->Startup and Recovery->Settings->System Failure: uncheck "Automatically Restart"

No above solutions are of work,plz tell me any appropriate solution i think only a person who knows motherboard repair can help me here.

you changed processor and RAM , but you suspect graphic card ???

i told you there can be hundreds of reasons

if you have no more detail , better bring to repair-shop

just f8 b4 windows logo on startup,,
choose
do not restart on system failure,,,
+carry on boot up,,
this time you have blue screen,,,(BSOD)
tell us the error code at bottom of screen,,,
at bottom of screen it say
STOP ERROR: 0x00000011 is an example
with above example 11 stands for any number 0-9 and any letter a-f (or hex in other words)
just post the error code you get.....
all rest of screen not worth anytin,,,unless it mention xxxxx.sys at top part screen,,,,(xxxx=anytin)..
good luck

at the first you check weather the problem is software or hardware i will give you setps follow them and tell me the result

1- try to run the pc without H.DD , i mean just run it at BOIS or DOS screen
if the pc restar after 2-3 mint that is mean ur processor hot solution check the cpu fan
2- if not restart , plug ur HDD and run the OS under save mode by press F8
and wait for a minunts dont run any progam for awhile if not restart try to open any program if restart check ur RAM. solution try to change it or if u has tow RAMs use one .

tell me the result to coutinue

tama isolate mo maige kung ang problema mo sa software ba o sa hardware.....

dude open ur computer take out prosseser fan and see that there is cooling paste on prosser or not if not add some of that reply