PS won't recognize scanner after reinstall

What a mess, and I'm the one who made it!
A while back, I got the TotalTraining Video to help me learn PS(7), and the first thing it had me do was reset some sort of color setting (this was so long ago I can't even remember the details), which resulted in a color-mismatch warning message every time I'd try to open something through PS - all I had to do was say okay, and it would open, but as I got tired of doing that, I went in and tried to undo the settings. That didn't work, so I decided to just delete PS from my HD and reinstall it so I could start with a clean slate. Bad move: first of all, it didn't fix the problem, but what's worse is that the reinstall somehow severed the relationship with my scanner (CanoScan 5000). I have a very vague, dim memory of doing something way back when to somehow establish a relationship between PS and Scanner, but can't even begin to know what it was. Anyway, I tried the delete/reinstall thing with the scanner (which didn't work 100% - one of the sections just would not "take", so I just proceeded with the install as best I could.) Anyway, it was all for naught, as the scanner still doesn't exist for PS. Any ideas?
Thank you in advance!

You are better off scanning in the scanner software.

now you can work in Photoshop while scanning.

Uninstalling photoshop does not erase its settings, deleting its preferences does. Hold Command+Option+Shift as soon as Photoshop loads to do so.

"... doing something way back when to somehow establish a relationship between PS and Scanner, but can't even begin to know what it was."

Try this:
in your Applications folder for PShop:
/Plug-ins/Import-Export/ (your Canon scanner plugin here)

Hi everyone -
thanks for writing back - don't all point and laugh, but I am SO low-tech that I don't even understand what all these suggestions mean.
Buko, I can't even remember why, but I was strongly advised to have it go through PS and I've been deliriously happy with it for years; I wouldn't even know how to do what you're suggesting.
PE, do you mean that if I do the key thing it'll delete the preferences and fix the problem? I really don't understand this at all - sorry, but I'm really clueless...
Susan W, do you mean that I'm supposed to drag the Plugin folder out of CanoScan and into the PS Import/Export folder? That actually made sense to me, so I did exactly that and restarted computer, but Scanner still doesn't show up in its usual spot under PS's Import/Export in the menu bar.

Just click on the cannon scanning app. you will see the same interface that you would if the plugin were installed in photoshop. Now you can work in Photoshop and scan at the same time. I have not used Photoshop to scan since I moved to OSX when it was first released

Just click on the cannon scanning app…

Double-click. ;)

Buko -
thank you for writing back - I am absolutely humiliated at how stupid I am, but I just can NOT figure this out. I tried the CanoScan app, but can not understand its interface - it's a little box that looks nothing like the PS version; there's no "preview" button (which allowed me to look at what I'd put on there and crop it as I saw fit); in addition, when I hit "scan" it tells me "specifies the program where scanned image is transferred" and gives me another box full of options that I don't understand.
I just want my PS interface back!!!!

I just want my PS interface back!!!!

then reinstall the cannon software.

I have never used Cannon scan software. But they all work the same. the plugin is linked to the stand alone app. So any interface you see in the plugin its there some where in the stand alone you just need to find out how to turn it on.

Eva, did you disable the TWAINplugin? because Photoshop would not start?

Hi Buko -

I DID reinstall the CanoScan software, but as I mentioned, not all of it "took" (perhaps something on the CD corrupted between when it was new and now?) - there were seven different sections during the installation and one claimed that it couldn't install, so I just kept going with the rest till it was done. Would it help if you knew the name of the stubborn section? I could delete the app and try again...

Of course, I have no idea what TWAIN is... :( (other than a very clever writer with a white mustache :) )

I'm not sure what you mean by PS not starting? PS works just fine, it's just that the CanoScan option no longer appears under Import/Export like it used to.