Mouse and keyboard randomly stop working

Hello everyone, this problem had started for me only about 3 or so days ago, and is rather annoying. What happens is that randomly while using the mouse, it would freeze up and I would hear the "Device Disconnect" sound, and a second later the mouse would work again. This happens absolutely randomly, and after a bunch of times, both the keyboard and the mouse completely stops working. They are both connected to the USB ports on the motherboard at the back of the computer, and unplugging and replugging does not make them work again. I have tried plugging them into other USB ports, such as in the front and top of the PC, and they start working again, but only temporarily until they once again stop working completely after like 10-30 mins or so. The only solution to get the mouse and keyboard working again [temporarily], is to restart the PC using the main power button. When they stop working, the numlock light is still lit on the keyboard, but the keyboard does not respond, and I have a small indicator light on my laser mouse that just starts blinking, when it normally has never done that. Everything else is still working, such as any music playing, and the internet. I have read soooo many forum posts on the internet and have tried sooo many different things, and nothing has worked thus far, and that is why I am posting, so that perhaps someone could find a solution. Things I have already done:
I have uninstalled and reinstalled all the usb, mouse, and keyboard drivers (from both the device manager and the actual drivers CD of my computer). I went to msconfig and set it to Diagnostic startup and did a restart, thinking that perhaps something might be interfering, but nope, still did not work. I have restarted the computer in safe mode, and this problem persists even in safe mode! I have went to the Power Options in my control panel, and under the USB setting, made sure that it was already set as "Disabled".
I have no clue what precipitated this issue, and I am absolutely dumbfounded in how to solve it. Many different forum posts, have suggested this might be some sort of power issue. But I don't really believe that is the case, because I only got my current computer at the beginning of this year, I've never had an issue with my keyboard or mouse, and I've never once seen the CPU usage go to 100%, even when playing some high requirement games. If anyone has any other suggestions, I would be more than happy to try.

Thank you for replying.
As I've mentioned, I've ran my computer in Diagnostic Setup and even in Safe Mode, and the problem persisted during both of these, indicating that the problem has nothing to do with any current programs or antiviruses running on my computer, as no services or startup programs are enabled during Safe Mode.
I am not getting any BSOD, it is just simply the issue of my mouse and keyboard that randomly stops working. If this is the wrong section of the forum to post this issue in, then please direct me to the correct one.
That tutorial link you provided absolutely did not help, and I even tried it before posting on here. Deleting the INFCACHE.1 file over and over, does not do anything, and does not make my mouse or keyboard work again in those usb ports.
And yes I have done the sfc /scannow and the chkdsk /f C: in the cmd menu. Neither of which have proven useful.
As for the BIOS update, I checked today on the Dell website, and the BIOS version of A06 is the most current one for my XPS 8300 PC.

The mouse and keyboard themselves are not the problem, they function perfectly on other computers. I plugged in a different mouse into the USB port that my mouse was connected to, after it stopped functioning, and there was no response either from that new mouse.
Also I plugged in a flash drive into the same port where my mouse/keyboard stopped working, and the computer opened it up.
All my drivers are up-to-date, and yet it seems to me that it still might either be a driver or a power problem. I can't figure out if the problem has to do with the USB drivers, or the keyboard and mouse drivers, or a power issue, or perhaps something else entirely.
I just don't know, and I'm getting frustrated in having to restart my computer like 20+ times a day.
If you or anyone else has any other ideas, I'll gladly try them out. Or any additional questions that I can answer.
I just don't want to reformat my HD, only to have this problem continue. Or worse, having to get a new computer.

Try updating the chipset from the PC or mobo's Support Downloads webpage. If it's latest, uninstall then reboot to reinstall the USB drivers. Are you perchance missing Enhanced USB driver?

I understand why you believe the mouse and keyboard are not the problem, but I would still try another just to be sure.

Is this the original factory preinstall, or an upgrade from Vista? If not when was it clean installed, and how closely did you hew to the Best Practices laid out in Clean Reinstall - Factory OEM Windows 7 which are same for retail?

Hello again. Thank you all for replying to me. I uploaded my System Specs.
Anyways I finally managed to figure out what the problem was. It was the mouse itself. I did what you guys told me. I unplugged the mouse that was causing the problem, and hooked up a completely different mouse, and experienced no more freezing throughout the day. I then took the problem mouse and plugged it into another computer in my house, and the same problems occurred on that computer.
Initially I honestly did not believe that the mouse was the problem, since it would work just fine and then freeze after like 30-60 mins, I thought this was a driver or a USB port problem. So from my speculation, what I think happens is that the mouse somehow overloads the USB ports, making them unresponsive or does something to the drivers, I don't know.
Anyways thanks a lot for all of your time, help and patience.

By the way, I just wanted to know for future reference, where do I go to find the BIOS options, to enable or disable the "Legacy USB support"?