if you're absolutely sure you had USB 2.0 before your reinstall, do the following:
Go through the BIOS and make sure all USB is turned on and, if configurable, set to 2.0.
Some of your ports might be USB and others USB 2.0. The manual may provide some insight here.
Find the latest Via USB or 4in1 drivers for your board. Most likely through via.com.tw, or viaarena.com. Looks like the Via Epia SP series drivers are at http://via.com.tw/en/products/mainbo...erboard_id=261