Photographic Negative Scanner

[#1]

Not sure whether this is a H/W or S/W problem. I have a Dell GX270 with XP. A few years ago, I bought a photographic negative scanner, and started putting all my old 35mm negatives onto my pc. Yesterday, I found some more negatives so reconnected the scanner and tried scanning them, but now I cannot get the software to see the scanner. The scanner uses a USB port. The USB port on my pc works - I tested it using a memory stick.
To test the scanner, I was allowed use another pc, installed the software, and scanned some of the negatives on that pc, so the scanner works, as does the software. I cannot keep using that pc so I went back to my pc, and tried again. I even tried re-installing the software, but it wont re-install while the old software is still there, and "Add/Remove Programs" doesn't list this software. I tried just deleting the software using Windows Explorer, but some files are locked. However, at least Explorer did a partial deletion, and I was able to reload the software, but my pc still says it cannot see the scanner.
Any suggestions please
Thanks

[#2]

Try using USBdeview (google it) to clear out the device drivers.

[#3]

Thanks for your suggestion. I have just tried USBDeview, but the list it produces did not include today's attempts to use the scanner. However, it mention it yesterday, and I deleted it, and then I was able to go into the program and Uninstall it.
I have now re-installed the software including the driver, but it still says the scanner isn't connected, and USBDeview doesn't list it either.
Never mind, it was worth a try

[#4]

Suggestions only !... no guarantees..
1.  download and install " Absolute uninstaller".... try that.
2. if it finds it and unistalls it.    Shut down the pc..... then connect and power up the scanner.... then power up the PC...
it may find "new hardware"... ( or it may not )... 

[#5]

Would you believe it. I plugged the scanner in to my pc tonight, and the pc immediately indicated that there was new hardware. The scanner has worked perfectly since then, so I haven't needed to try Shutter's suggestion (thankyou Shutter, anyway).
Thanks to all

[#6]

Life is like that  ! 
(perhaps I could set myself up as a remote "fixer" and do it all telepathically.....    )
on the other hand.... it might not work... so it would be done  tele pathetically ! ! 

[#7]

Yeah! Merry Christmas   

[#8]

/Strat goes off to plug in his negative scanner to see if it works
Come to think of it I have a ClimaxDigital Scart to USB cable I bought for VHS conversion to DVD.
It also suddenly refused to be recognised by my PC. I'll have to dig it out and give it another try.

[#9]

Question.....
How can you be positive, that a negative scanner works.... surely if you scan a negative, you will get negative results, therefore, you can`t be positive that it is working.

[#10]

You're just being negative about the whole thing.
Make with the positive vibes man