I have a 1.65 gigahertz Intel Pentium Dual processor on my Windows 7 (32-bit)desktop but it sometimes runs slow and even stalls.
Would an upgrade to 2 G/Htz or higher speed up my system?
If so which is the best to buy?
A strictly better processor can only ever help your system.
However, I can't guarantee that the upgrade will be sizeable.
I also can't suggest anything specific at this point, because I need to know a whole lot more about your current hardware. Exactly which processor, exactly which motherboard, is it from an OEM PC maker like DELL or HP, and that sort of information.