I have a Dell inspiron laptop with windows vista. It has been working perfectly until lately, a problem has been bugging the hell out of me. Ever minute, a USB safe removal notification in the battery/time bar keeps popping up. It disappears instantly. The sound also plays every time. This by itself didn't bug me, until it started to slow down my computer momentarily every 5 seconds or so. This also happens even though there isn't a single usb plugged in (including mouse, printer...) Please help. Thanks
As Ramhound mentioned it's always a tussle of trying to find out if its hardware or software that's causing the problem.
If you load your Device Manager in Windows you can expand down Universal Serial Bus Controllers and double click on each USB Root Hub then click on the power tab within here you will see if any devices are 'plugged in' (or at least se if Windows thinks they are plugged in).
Within the Device Manager you can also right click on your USB Host Controllers and uninstall them, restart your machine and they will re-install, giving them a fresh install could solve the issue.
Finally reinstalling Windows might solve the issue but not if the issue is hardware.
Sorry I know this is not an 'answer' as such but too long for a comment, hope it helps.