sorry for not mentioning the specs. it's a Packard Bell iMedia x2416. i already bought an nvidia 9800 GT but i had to remove it after few days because is making a noise from the fan and is also getting very warm.
Pretty much any modern video card is going to get hot and/or make a noticeable fan noise. You can reduce this by getting one of Sapphire's Vapor X coolers or something like that but it will still get hot. Just make sure your power supply is hefty enough to meet the power requirements of the new card. 400W+ is recommended