Windows 7: Need help immediately!!

sorry for bad spelling now let me explain.!!!!! ok so i have wndows 7 ultimate. i have a dell optiplex 755. now i needed to install libusb to take out my iphone from recovery mode. ( i didnt need it after all i found a new program). BUT ONCE installed it changed all my usb port so i cant use them!! keyboard mouse dont work AND no i do not have ps2 ports on my motherboard... i do have windows 7 cd i tried restorign it to a point 3 days before but no change...

so heres a list of things i tried

-restoring
-ps2 kebyaord mouse
-remote desktop

stuff that i have Windows 7 Ultimate x64AY

windwos 7 ultimate
the cd for it

try:

SFC /SCANNOW Command - System File Checker

i cant log into my pc password protectd keyboard mouse dotn work safe mode same thing..

We cannot discuss how to crack or circumvent passwords. With all due respect, we do not know if it is your computer. I suggest you take the computer to a reputable computer shop and pay for their help in solving the problem.

Boot the Windows 7 DVD, select Repair My Computer on second screen, let it discover an installation to Repair, then click through to Recovery Tools list to run Startup Repair repeatedly until it starts correctly.
You may need to run it up to 3 separate times with reboots if there are complicated issues.

Report back if no installation is found to Repair. Accept System Restore as an option if offered by Startup Repair utility. Also, the first offered Repair when you boot into Repair console does not count as a Startup Repair if it doesn't start the computer, which it may not.

Have you tried wireless keyboard/mouse?

dose the keyboard/mouse work at booting (like can you get to your bios ) ?
if not maybe resetting the cmos will fix it.
scrooge

carl: ofcourse its my computer ican even list the specs and everything about it even the bill for it!..
ezio: wirelles keybord mouse work with a uss receiver in the computer so it wouldnt work...
gregrocker: i dont understand i can restore to a previous date.. but when i press repair it tells me it finsiehd and it should work... if i do it 3 times hopefully it works..?
SCROOGE!: IT WORKS ON THE STARTUP! PLEASE EXPLAIN HOW TO FIX IT FROM THERE i can get into bios

ok well if it works before booting to windows then what i was thinking will not help you sorry...
scrooge

darn this one will be hard to solve i really dont wanna reinstal..