I have a Dell 15R 5520 laptop, on which I have a dual boot of Windows 10(64) and Windows XP(32). All is well, apart from one thing which is quite agonising! I'm having trouble with the USB on Windows XP. The laptop won't seem to recognise any USB device inserted. The ports work fine on a Windows 10 boot. I've tried installing drivers from the Dell driver pages and a USB 2.0 exe file from Intel. Nothing will allow the laptop to see a USB device when logged into XP. I have SP3 installed. Device manager shows Realtek card reader USB, root hub, generic hub, standard enhanced PCI to USB controller and USB composite device. There is a question mark underneath USB Device in "other devices". I've tried manually pointing the driver wizard at various files like usbhost.sys /inf etc ... nothing happening. Wondering if someone with more knowledge than me can assist!