Can I scan old slides to my computer? What do I need if that is not possible?

Yes a Scanner that can handle slides. Most film scanners will do 35mm slides. Is that what you have as I have been doing photography for 40 years and never heard of 2x2 slides unless you are taking about the hold the slide is mounted in. That is a 35mm slide.

Slides are what is called transmissive, as opposed to reflective (papers and prints) subjects. Scanners that can scan slides have a backlight or attachment that shines light through the slide to the detector.

A scanner to scan them and possibly a frame to hold the slides. Check out the Epson Perfection V700 Photo scanner.

Shootist007 I think the OP means 2 1/4 x 2 1/4. Surely you've heard of those.

No he mean 35mm. The slide holder is 2" X 2". And yes have many 2.25SQ Slides and Negatives.

Yes you are correct.

Or the V500, which I have and can recommend highly for slide scanning. For about $150, it outperforms the $2000+ Nikon dedicated film scanner I bought 9 years ago.