When i on the system, the fan is not rolling, sometime when on and boot upto the the window evironment, its shut itself down. what could be the possible problem with them

The fan on the system is not working and computer shuts its self down because it over heats ... and this can cause permanent damage, the best thing to do at the moment would be, that you get a technician to take look at the laptop, don't use the computer till then.

Please Check CPU making any noise or not.

remove the CPU side door and check Fan is rotating on Processor if not it may not rotate due to heavy dust inside. ( clean it and refix it)

Check SMPS Fan is rotating or not..

If fans or not rotating Heat Builds up then computer shuts down itself.

If both fans are working...Just Open BIOS window by press DEL button continuosly while startup and wait for 2 to 3 minutes If the computer shuts down Itself in BIOS Window also then we can confirm issue with Hardware.

If Computer not shutting down in BIOS Window then issue with Operating System Boot files corrupted.

While Turn ON the system press F8 to enter in Safe Mode.

Open command prompt by clicking on

Start >. RUN >> type cmd >> then press enter.

now type chkdsk /f

now press Y

then reboot PC it fixes the Boot files error then your PC works perfectly.

If you still exp same issue let meknow..