It is not for virus.
You can do another ,
Follow the bellow instruction.
It may be the operating system has not recognized all the ports, if you operating system is now ok, go to my computer>properties>hardware>device manager, and look to bottom of the list to USB Controllers.
right click on them, and Uninstall all controllers and restart pc and see if all the ports are recognized and installed automatically.
Go back to the controllers after restart and ensure there are no'!' marks or no 'X' against any controllers
It can Also fails, you might have a problem with your bios. You might want to update your bios (but of course this involves some risk).http://support.dell.com/support/downloads/index.aspx?c=us&l=en&s=gen
Flashing as said earlier involves some risk and the instructions must be followed strictle. Please don't switch off the power at the time bios updating .SHOULD USE UPS /AC ADAPTER always.
Hope this helps.
If think about virus do it .
You want to save your data with out Format
all thepartition ,download hiren boot, from the bellow link.http://www.hiren.info/bootcd-on-usb-disk
Now burn the ISO file, under image burning option
,from nero ,in the another pc which is run's well. Restart pc, the cd will start soon, if the hiren boot cd ,willnot run, set bios setup. Now click here
for BIOS SETUP ,restart again and select miniwindows and delete system volume information and RECYCLER from all the partition or drives except "C"drive
Because "systemvolume information" and "RECYCLER"
is the Heart of Castle. If it not removethe virus ,download bootable f secure
And write the ISO under image burning option
,from nero and boot from CD. Now you can scan for fix.
Insall clean OS, delete partition C: and create C same .
If you do not want install the OS ,download c
ombo fixfrom bellowthe link
Follow all the steps.Rstart the pc >press F8> select save mode usethe down arrow key .copy and paste the combofix and dubble click on it and wait for few minutes. Do not do any thingwhen the combo fix will be running.Let them do .
If you need more information, reply me soon.