My pc not recognising USB flash drives

Ok so here it is, my pc is not able to detect usb flash drives.I searched on google and saw some answer about looking into disk management, but it does not show up here either.

I have tried Pendrives, Ipod and PSP.Neither works.The lights in my pen drives light up so its definitely not a problem with the hardware.The weird thing is that i can connect to the internet with my USB DSL.However i noticed that if i reboot my DSL, i have to restart pc again because it wont recognise the USB DSL router.

I have tried inserting my USB flash drives before i start my pc like the router but nothing.It doesnt work.I have also checked in BIOS, and they are all enabled.Im running out of ideas and i cant backup anything in my pendrive.

Are these the front USB ports ? ?
Some are notoriously under-powered while others are never even connected.

No i tried in all 4 back ports but nothing.My keyboard and mouse works perfectly tho

No thats the problem, i dont see it

EDIT: Didnt see Shawn's post, it solved my problem.Thanks a lot really helped me

Ok, it worked for one day, but when I restarted my pc today it do the same thing again.And using the registry wont work anymore.Any other fixes for this?

Go to EVENT VIEWER. Left hand side, Application -> Microsoft-> Windows -> DriverFrameworks-Usermode -> Operational.

Those are the power events for connected USB devices. Scroll through and see what info it provides.

They all say "Driver Manager service started successfully"

Muhsin said:

They all say "Driver Manager service started successfully"

There should be a half dozen events for each connection/disconnection. So, no errors and all looks fine?