I have an Epson 1670 scanner hooked up to WINDOWS xp on my pc. Last week while trying to scan a PICTURE I got a message saying
" scan could not be started could not open twain source make sure it is a valid source for the scanner.
I have never had any problems with this scanner in the 2 years I've owned it. I tried opening it from its software INTERFACE and got a message
"unable to start the scanner because it is not ready or another application is using it"
The scanner is ready and I can't think of any other programs that is using it. There might have been a problem with a Trojan virus I downloaded 3 weeks ago. I discovered it and had to purchase and INSTALL DOCTOR spyware to remove it. It removed it but I seem to recall some kind of twain source message that flashed across my screen at the time. Is there a connection? A friend said to go to device manager and uninstall the drivers, then go to windows twain directory folder and delete its contents. I went to device manager in the control panel and open the folder but it was blank, no scanner nothing just a blank folder. This got me thinking that it might be more than just a simple problem. any suggestions for the next step would be greatly appreciated.

Thanks
pursuant....... The easiest thing for you to try would be to completely uninstall your scanner .......including any drivers .....reboot and make sure its gone ......and then reinstall it . ( I assume you have the cd which came with your scanner )
That should solve your issue .
Are you certain that you have removed the trojan ?

dl65  
I have done a uninstall from the add/remove section of the control panel, a couple of times. Does that remove the drivers as well? I know there is a twain folder in windows directory, does that have to be removed too?
As for the trojan...well I think so . I downloaded  Doctor Spyware and it seem to catch quite a few things. I ran a list of exe files in search and found one that I looked up and it was one of these trojan files. I deleted it. I run spyware everyday and I'm not catching anything that appears bad so at this point I think I got it but I am not positve. I run 3 spyware programs and I have an updated antivirus program. I hope this is enough.
Thanks again for the suggestion