i bought new optical usb mouse toady but it is very jerkyl while controling it or move in zig zag path when leaved freely or moves very hard or can say pointer is very unstable and also happens same with another usb mouse of my friend, some time i feel that i am using that old ball mouse, but have tried my friend's ps2 mouse but its working f9
The jerkyling is likely the result of the proper driver needing to be installed. In addition, Control Panel should offer a mouse icon which when opened would allow for the mouse movements to be adjusted to help to get things mouse related working fnine.
A mouse with Windows 7 drivers available from the manufacturer will likely be more acurate, etc. than an older mouse with no specific Windows 7 driver available. Windows 7 has a basic 'system' mouse driver built in in case no specific applicable mouse driver is installed.