Lenovo laptop suddenly could not recognize any USB

Hi, all. I'm new to this forum and to Windows 7, actually, because I just recently had my dad's Lenovo 14001 upgraded from Vista to Window 7 Ultimate. The only reason we had his Lenovo upgraded was because we encountered the "0xc00000e9" problem (i.e., the one that says "Windows failed to load because the system registry file is missing or corrupt... status 0xc00000e9"). Upon advice that it'd be best to upgrade to Win 7, we then upgraded his PC last March 30, 2013. After Win 7 installation, everything was fine. We didn't encounter any problems. Then just now, or a week later (April 6), the PC could not recognize any USB. I have a flash drive and a mouse here that light up when inserted to a PC. But now they won't light up. I checked Disk Management to see if the flash drive's "found" there but there's only the Local Disk [C:] and the DVD Drive [E:]. I've googled answers and tried suggested remedies, but none so far worked.

So I'm thinking (we're not techie persons and we use our PC for office and business work, so sorry if my wild guess sounds stupid), since the PC is around 6 years old, maybe the problem's in the actual PC unit? Lenovo 14001 is after all an old unit--i.e., unlike laptops today, it has no webcam or bluetooth, etc., and it shuts down unexpectedly when it gets too hot.

Any help would be appreciated.