WSS3.0: Search Scope not showing up

The scenario you've described is completely possible. It will take a few steps, and I'm happy to walk you through them.

For others reading this thread, when beginning an upgrade from WSS 3.0 to Search Server, your best bet is to follow along with the steps in the document "Upgrade to Search Server 2008 from Windows SharePoint Services 3.0"

In that doc, in the section titled "Activate features for Web applications carried over to Search Server", ensure you've followed these steps:

After you install Search Server over Windows SharePoint Services, you must activate features for the Windows SharePoint Services Web applications that were carried over to Search Server. Use the following procedure to activate features for these Web applications.

To activate features for Web applications carried over to Search Server

1. From the Central Administration Web site, click Application Management.
2. On the Application Management page, under SharePoint Web Application Management, click Manage Web application features.
3. On the Manage Web Application Features page, click a Web application.
4. Next to the description for Office Server Enterprise Search, click Activate.
5. Next to the description for Office Server Site Search, click Activate.
6. Repeat steps 3 through 5 for each Web application listed on the Manage Web Application Features page.

Reading this document again, I've noticed that there's a key step missing in order to make your legacy search boxes take advantage the new Search Center experience. I'll request the document be updated to include the following steps.

For each WSS Site Colleciton that existed prior to the upgrade, complete these steps:

1. As a site collection administrator, click on "Site Actions > Site Settings".

2. There will be some new links in the Site Collection Administration column which have appeared as a result of activating the features. Click on "Search Settings"

3. (Now I admit that this page is not intuitive. Just take my word here for what it does...)

There are two radio buttons. Select the one called "Use Custom Scopes".

In the text box, type in the address of your Search Center. The exmple given on that page might be a little misleading. If your the new Search Server Search Center query page is http://[servername]:[port]/default.aspx and the results page is http://[servername]:[port]/resutls.aspx, you can just type in http://[servername]:[port]

Now, if you navigate to a page in your original WSS Site, you should see the following changes:

1. The Scopes Dropdown now includes "All Sites". (You can add more scopes by using the Search Scopes link which is directly below "Search Settings" in Site Collection Administration)

2. When you type in a query, it should now show the results in the Search Center's results.aspx page.

REF: http://forums.microsoft.com/TechNet/ShowPost.aspx?PostID=3020163&SiteID=17