Depends on the context. Sometimes they mean the same thing, and sometimes not. for example, both can mean "to cause something to exist again", meaning it stopped existing at one time but now it is back again. ex. "peace was restored to the country" = country was peaceful, then not peaceful, then peaceful once again. "peace was reestablished in the country" = the same however, sometimes restore can simply mean to clean or repair something to its original condition.... meaning it never stopped existing, it's quality just decreased... until it was restored. "After hours of cleaning, the kitchen was restored to its original state" "My dad restores old furniture" Hope that helps. It's a tricky question to answer.

Both initially mean the same thing however restore is used more when talking about technicf al things such as computers or to "restore messages" where as reestablish is used more when speaking about business contexts such as to "reestablish a company" or "reestablish a plan" , but you can still use both however you want