Have no USB support- cannot access computer with usb keyboard and mouse

[Grateful2]

I have a Dell Dimension 9100 with 1 gb RAM, Pentium D chip, and 2- 160gb harddrives that I have partioned into 4 total drives. I run Win XP Media Center Ed. 2005, which is really a fancy XP Pro.  This machine only has USB ports in addition to the monitor port.

I had a virus I could not get rid of, so I reformatted and repartitioned both hard drives like I had it.  There was a separate 256mb partition that had the MBR in it, so, thinking I needed that,  I didn't reformat it.  I wonder now if the virus hid there. I reinstalled Win XP MCE 2005 without problems and I reloaded a couple of Dell drivers, when suddenly a big, flashing, rectangular box appeared on the desktop saying it was installing programs, not to interrupt, and that it could take up to 30 minutes to complete.  After that was finished, I discovered that my USB ports no longer operated, hence I had no working keyboard or mouse. I tried to reboot from the DVD, but I could not press a key to start from the CD as it asked, so it merely booted to the Windows desktop, where I can go no further.  I am stuck!  I have no idea where to go with this.  Is there some way to turn on the usb ports manually on the motherboard?  I couldn't get into the setup screen either because I couldn't press F2 after the Dell screen.  Would a new hard drive make any difference?  Does anyone have any ideas?  I appreciate any and all help.

[michaewlewis]

Try plugging the keyboard into each of the usb ports.
Turn off the computer and unplug it for 15 minutes to make sure all the power is drained from it and try again.
Try a different keyboard/mouse.

[patio]

This is why everyone should have a spare PS2 mouse and keyboard...if the OS doesn't load properly the USB ports are worthless...
It won't cost much...and you'll have them for such emergencies.

[michaewlewis]

This is why everyone should have a spare PS2 mouse and keyboard...if the OS doesn't load properly the USB ports are worthless...
It won't cost much...and you'll have them for such emergencies.

This machine only has USB ports in addition to the monitor port.

a lot of the new dells don't come with ps/2 ports.
A call to dell tech support may be in order.

[Grateful2]

Dell won't talk to me anymore.  I had a three year contract (purchased computer from initial owner unused) and was told I had the rest of it.  After the first year they deleted the 2 extra years which I had seen on numerous occasions in the past, and I can't even talk to a human because I have "no" coverage.  Otherwise, I would have called them right off. 

I did try changing the usb ports, and I discovered that there is a 1 second window where the usb port is on right at startup (I could tell by the little green light on the keyboard) so I started pressing keys as soon as I saw that, and it was enough for the Windows Installation DVD to start.  So, I've deleted the Windows partition and am reinstalling to that partition now.  I will let you know how this turns out.  Thank you very much for your suggestions.  And a PS2 port may be something to think about on my next machine as a backup! 

[patio]

So you're saying you don't have these on the back of your machine ? ?

                                              .

[street1 (RIP)]

Sometimes resetting you BIOS  to defaults fixes this problem
when you don't have PS/2 capability.

Jumpers on motherboard,or CMOS battery is the normal route.

[Grateful]

Patio- Yes, those ports are NOT on the back (or front) of my machine.  I had to purchase a ps2-to-usb connector initially in order to use my older mouse. 

Update-  I am continuing to reinstall Windows and all the drivers.  So far so good.  I was told by Dell forum people that the first driver to update is the Desktop Management driver (on Dell machines) which includes support for all kind of USB connections.  It's also called smb driver (System Management something).
I hope these bits help someone else down the road when they encounter this problem.  I'll add to this as I learn more about it.

[patio]

Actually Dell does a very good job on their support info in most cases...if not the Forums there have tons of info.