Here is one thing to try:
To edit your Classic ASP files and still utilize syntax highlighting and intellisense. You need to associate the .asp file extension with the Web Form Editor. When doing this you are telling the IDE to treat .asp files the same as .aspx files, in turn sort of tricking the IDE in to giving you the syntax highlighting and intellisense that you want.
The steps in setting up the IDE are as follows:
1. Open Visual Studio
2. Goto the "Tools" menu and click "Options..."
3. Check the "Show all options" checkbox in the bottom left of the dialog box.
4. In the right pane expand "Text Editor" and select "File Extension"
5. Enter "ASP" extension in the "Extension" textbox
6. Select "Web Form Editor" in the Editor dropdown box
7. Click the "Add" button and click "Ok" on the dialog box.
Found it here:
http://social.msdn.microsoft.com/Forums/en/adodotnetdataset/thread/d7776d82-40c7-4618-b375-87fd4dc947be[
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