First thing you need to do is right click on My Computer, clickProperties, click Advanced tab then on the Start up and Recovery click the Settings button and uncheck Automatically Reboot, this should at least tell us what is causing the problem when you plug it in again you will get an error system.

Sounds kinda like an IRQ problem or you may not have enough power to supply all of the usb ports you are using. Try unplugging what does work and then plug one of the things that does not and see if that triggers an error.

You may want to try updating the usb drivers also.