i have a dell optiplex 745 that i had running with xp. i recieved a new harddrive that had been loaded with windows 7 and tried to get that installed and running. everythign worked like a charm! infact it even started and finished downloading the new updates for the oS that were needed. it restarted after installing the updates and this is where things started to get a little funky... when i restarted the computer, the usb ports stopped working... ALL of them... so i restarted the computer and went into BIOS and the key board worked fine and checked everything and then exited the BIOS and as soon as the Windows symbol appears, the keyboard shuts off as well as the mouse and any other usb devices that are connected... so i was a little perplexed... so i reinstalled the old harddrives (with xp) and bam... no problems at all with the usb ports. switch back to the 7 hard drive... and once again... the problem begins again with no power to the usb ports. i even installed both hard drives at the same time (with the xp being the "master" and the 7 being the "slave") and it worked fine and could even access files on the 7 hard drive and ran a device check on it and its perfectly fine... i called Microsoft and had a good 3 hour conversation with them and they had "Never heard of this issue before" and couldnt figure out a solution. sooo im leaving it to you all... please help me out!! if i left any information out write back and ill try and provide as much info as i can. thank you all in advance!
Where did you receive the new hard drive that had been loaded with Windows 7 from? This is a key question since if that hard drive was simply taken out of another computer that had different hardware in it and installed in your PC then all kinds of things could potentially go sideways. Based on the drivers that are available for the Optiplex 745 it appears the most recent operating system Dell shipped that model with is Windows Vista and from what you've posted here it seems the USB ports were functional until the computer was restarted to finish installing the updates that had been downloaded. Were those Windows Updates or some other kinds of updates?
im not sure to be completely honest about where the hard drive came from. this was kind of a work in progress in terms of building it up and creating my own "frankenstein" of a computer. the updates were Windows updates from the windows update section that shows up in the task bar lower right hand corner... it was an automatic update... idk if that answers everything.
oh the hard drive that was loaded with windows 7 actually came with the optiplex. i had 2 other hard drives (both with xp) that i was running on a dell dimension. i got the optiplex actually for the tower and was just going to use my two hard drives, but in the end i decided, why not? upgrade to 7 lol then everything went down
You might consider visiting Intel's download site and using their online chipset software update utility to download the latest chipset drivers (which will include the USB drivers).
Another potential pitfall is 'nonpresent' devices that hold resources. You can eliminate nonpresent devices in Device Manager to deal with this.