You can search for Sellers via the Advanced link to the right of the eBay Search window. Scroll down to the Seller section and enter the ID and complete the Search at the top or bottom of the page.

When was the last time you used the old account? eBay does purge accounts after a long period of inactivity - they send you an annual reminder to login to verify your info so your account remains active. If your account was purged, there is no way to get it back.

If you can't sign in to your eBay account Make sure Caps Lock isn't on. Look for spelling errors. If you recently changed your username or password, your browser might remember your old information. Try manually entering your new username and password.

You'll need to sign in to your account to access My eBay, where you can keep track of all your buying and selling activities, view items you've saved to your watch list, and find your favorite sellers and searches. You'll also need to be signed in to exchange messages with other eBay members.