There is no way to "upgrade" to USB 2.0, if you see yellow triangles in Device manager, it means that the device is not installed, so you can go to the manufacturers website (for example Intel.com) and download latest drivers.
If however there are no triangles and it is fully installed, you cannot upgrade a USB 1/1.1 socket to 2.0
If you really want USB 2.0, you can get a card that can give you 4 for really cheap (less than £5) if you look online, and possibly cheaper for eBay, won't be a named brand, but nearly all the designs are the same and should get the job done.