@ vishald - as comp@ddict has asked which cpu do you have - is it core 2 duo or pentium D cpu ( both of them are dual cores ). Can you mention the model number of your cpu ?
There are two dual types of intel dual cores ( 2.66 GHz apeed ) - one is pentium D 805 ( Pentium D series - no too good performing ) and others are Core 2 Duo E6700/E6750/E7300/E8190/E8200 which belongs to core 2 duo family and offers decent performance.
If you have the CVore 2 Duo E6xxx/E7xxx/E8xxx series cpu :
If you can get a good psu like corsair VX450W around 4K get MSI GTX 260 Twin Frozr around 10K and if you don't have a good PSU and your cpu belongs to pentium D8xx series then get HD5670.
There are two dual types of intel dual cores ( 2.66 GHz apeed ) - one is pentium D 805 ( Pentium D series - no too good performing ) and others are Core 2 Duo E6700/E6750/E7300/E8190/E8200 which belongs to core 2 duo family and offers decent performance.
If you have the CVore 2 Duo E6xxx/E7xxx/E8xxx series cpu :
If you can get a good psu like corsair VX450W around 4K get MSI GTX 260 Twin Frozr around 10K and if you don't have a good PSU and your cpu belongs to pentium D8xx series then get HD5670.