Donate: Check with your local Goodwill, the Salvation Army, or Muscular Dystrophy Association for their donation guidelines. The National Cristina Foundation (cristina.org) places refurbished computers in educational and nonprofit organizations for people with special needs. Generally, charities want computers in working order, with a Pentium-level or Power PC processor or better. Delete personal files, but be sure to leave the operating system and licensing information on the computer. You can find more tips on computer donation at techsoup.org.
Sell: Computers are one of the best-selling categories on eBay. If your hardware is up-to-date, it could be worth the effort of putting it up for sale online.
Trash: If your computer is more than five years old, it's probably best to recycle. Organizations such as the Computer Recycling Center (crc.org) accept obsolete computers and recycle unusable parts to keep them out of landfills.