Thanks for your post and sorry to hear you are experiencing some issues.
Firstly, please note that the 2i2 us untested and unsupported on Windows XP, as such, there may be issues that we're not aware of.
To ensure that Windows as assigned the correct driver, please navigate to Control Panel -> Device Manager -> right-click on interface in Sound, Video & Game Controllers -> Update driver software -> Browse My Computer -> Let me pick from a list -> Ensure 18.104.22.168 is selected and click Next
Please look through the following optimisation steps and power management settings:
Have you tried all other USB ports? Some are internally hubbed and can cause issues. Please try each one and monitor the performance of the interface.
Please ensure you have disabled power saving mode for USB devices:
In the device manager (Start > Control Panel > System and Security > System > Device Manager), in the Universal Serial Bus controllers section, right click each USB Root Hub, choose Properties > Power Management and untick the Allow the computer to turn off this device to save power option.
If using a Laptop, it could also be worth checking the general power management of your computer:
Go to Start > Control Panel > System and Security > Power Options.
Set the Power Scheme to High Performance (if this setting is not available, click on Show additional plans first). Then click on Change plan settings. On the next page set both Turn off the display and Put the computer to sleep to Never.
Then click Change advanced power settings. In the window that opens make sure you have the following settings:
Hard disc > Turn off hard disk after > Setting (Minutes) = Never
Sleep > Sleep after > Setting (Minutes) = Never
USB settings > USB selective suspend setting > Setting = Disabled
Display > Turn off display after > Setting (Minutes) = Never
Processor power management > Minimum processor state > Setting = 100%
Processor power management > Maximum processor state > Setting = 100%
Please note, not all options may be available.
It could also be worth checking for any available USB/Chipset driver updates for your motherboard.
Are you using the USB cable that came packaged with the 2i2?
Are you connecting the 2i2 directly to your PC and not via a hub?
Please let me know how you get on
Simon // Focusrite Technical Support