If anyone knows how to solve this I'll be amazed.
it's a code 39 on Nec usb host controllers i..impossible to update a new driver because it doesn't exist + after uninstallation of a old driver doesn't wanna accept the new one coz it constantly gives a message that "can't find a better driver than the one installed" even if they are removed from system32 folder...Reinstallation of windows and flash bios doesn't solve the problem.Any opinions?

What os are you using?
Is the usb host controller 1.1 or 2.0?
Is it add-on or built-in?

Fairly important factors when asking for help.... :)

http://www.butterflymedia.com/TechSupportFiles/USB%20Problem%20Solver.htm

remove the controller then reboot your system/ make sure you have your windows setup disk handy.