Let me just say now that this is a long and complicated story and the problem is apparently not a simple one. I am praying someone here can help me out. A few weeks back, I got an A4-Tech X7 gaming mouse (XL-750BK). When I first got it, I was using an old PS/2 mouse and forgot that I had USB mice disabled in the BIOS. I plugged in the USB mouse and installed the new mouse's software off its disc. It actually worked despite the BIOS setting. Then I ran into big problems. I was playing with the settings, and increased the USB polling/report rate from 125Hz (default) to 500Hz and then 1000Hz. At 500Hz it was nice and smooth, but when I put it on 1000Hz it spazzed out and started moving erratically, 5 pixels at a time (total loss of precision). The left and right clicks also just stopped functioning. After restarting and still having the problem, I plugged in the PS/2 mouse again and put the setting down to 125Hz again. It was still crazy. I restarted, unplugging the PS/2. Still messed up. I then unplugged the new mouse and plugged it in a new USB port and tada! The mouse calmed down again but it did not move very fast even when on 3600dpi. At this point I remembered the BIOS setting and enabled USB mice. After this I could put the mouse on 1000Hz with no problem, but still have this problem that the mouse is not moving at its full speed. Current settings: USB mouse enabled in BIOS USB keybaord disabled in BIOS (didn't have any effect) USB polling rate is set to 500Hz Windows mouse pointer speed (sensitivity) is set to 6 (a.k.a. default setting) Windows enhanced precision is disabled. Running Windows 7 x64 Windows device manager reports that the mouse is "HID-compliant mouse" I did a test to determine the actual dpi of my mouse at its various settings, the results are below: I moved the mouse across the width of my screen in a straight line, and measured the distance it had moved on my mouse pad. I repeated each test and would say the measurements are accurate to within 0.1cm. I've been just using the mouse like this, on 3600dpi. All other settings are just too slow, and even this is too slow. I would probably be comfortable with 2000 "true" dpi. Please, any help or suggestions would be appreciated. Let me know if you need additional information.
