hi, i have a hp dx2200 series pc, intel, 1.5gb ram, 3.0ghz. i want to install a 64bit operating system. is it convinient to install the software ??

Which 64 bit operating system do you want to install? Installing a 32 bit or 64 bit version is the same process.

Have you verified that the computer in question supports a 64bit OS?

Assuming this system is 64-bit capable, then it should not be a problem. There are many 64-bit linux distributions you can download for free and install as you wish. FWIW, 1.5GB is not bad for many Linux distributions, but I would NOT want to run a 64-bit Windows system with that little RAM.

I recommend xubuntu for your PC, it is designed for not so good performing PC's, therefore offers a big performance boost.