Internet restrictions set on local computer

A previous tech had set Internet restrictions on some lab computers. These
computers are not on a domain. The restrictions are set locally. They
affect both the administrator and the student users. You can reach our site,
but no others. When you try another site the search times out. I looked in
the Local Security Settings and couldn't find anything related to restricting
Internet access. The hosts file also has not been modified. How can I
disable these restrictions?
.