Cant scan 4cm x 4xm slides

The MP600 cannot scan film or slides. Film/slide scanners need a light source to shine through the film to the scanner sensor. You can use a flat bed scanner with a light source such as the CanoScan 5600F, or a multifunction unit equipped with a backlight source such as the Canon PIXMA MP810, MP970 or MP980.

Click Start, choose printers and faxes, choose scanners and cameras, right click WIA Canon MP970, click properties, choose events tab, choose select an event, scroll to "attach to email".

Here you go:

http://www.tradebit.com/filedetail.php/4981055-canon-pixma-mp970-printer-service-manual

You don't state what Operating system you're using.

Start by following this link and then download any new updates/drivers according to your OS platform.

take and open the scan lid and take the glass//plastic off and clean off the lins

the colered pictures may be illegal to print like school pictures if you scan and then print them they will have a line threw them.

One workaround is this: use the holder for the negatives as a guide but not as a holder as such.
To do this, place the film negative directly on the glass plate, then put the negative holder (completely assembled) on top of it; align the film and the holder so that the frames on the filmstrip line up with the marks on the holder correctly.
Now, close the lid and follow the normal procedure for scanning negatives. They're noticeably sharper this way, suggesting that the scanner's focus is set for items placed directly on the glass plate. I have no idea why focus isn't adjusted correctly for negatives, which site a millimetre or two above the glass.

I've not ever seen "square" 35mm slides. By definition they are a rectangular positive film in an outer square "mount".

If you have a truly square piece of film then it is not a 35mm slide. You may have to use settings other than those for a 35mm film but these would be I don't know.

When were they taken (approximately)? What brand of film? Are they in a cardboard "mount?

Delete the printer from your system. Reboot. Reattach your printer and let it plug and play install. Make sure the printer is defined as your default printer. Make sure the application you are using it set up to use the MP970.

The MP970 has drivers available here which support up through Mac OS X 10.5. It can scan film and mounted 35mm slides.