Hp pavilion g7 noisy fan

[StarTanJawi]

I have a laptop problem that worries me sometimes when i turn on my laptop makes a noisy sound and when i restart noisy gone

my spec :

model : hp pavilion g7 notebook pc
ram : 12 gb
os : windows 7 x64
hard disk : 120 ssd
cpu : i5 2430M

 

[Blackbadger]

It sounds like the fan is having issues, maybe dust accumulation, or the bearings have gone. Also check if you have the latest bios.
If comfortable I would open the back of the laptop and carefully clean the fan and vents. If that doesn't work, a new fan will likely be required. They cost around £10, however it is a bit of a fiddle to replace.