You essentially need to make three sections in the document, then fix them up properly. First to make the sections:
1. Select the pages you want as the first section, pages 1 and 2.
2. Click the Page Layout tab on the Ribbon.
3. Click the little arrow in the lower right corner of the Page Setup group.
4. Set the Apply to list box to Selected Text.
5. Click OK.
6. Repeat for the second section, pages 3 and 4.
You don't have to do this for the third section; it's automatic.
Now do this to the second and third sections:
1. Click in the section.
2. Double-click in its header (or footer, depending on where you want the page numbers to go).
3. Deselect the Link to Previous button on the Ribbon.
You now have three sections with separate headers .
Now, in the first section, edit out the header or footer if it's not already blank.
In the second section, edit out the page number field from the header or footer. Also, do this:
1. Click the Insert tab on the Ribbon.
2. Click the Page Number button.
3. Click Format page number.
4. Click the Start At radio button. A 1 should appear in the combination box next to it.
5. Click OK.
This sets the second section to start page numbers at 1, but with the page number field gone, the numbers won't appear.
Now in the third section, repeat steps 1-5 above, but click the Continue from previous section radio button instead of Start At. Make sure the third section DOES display the page number.
Hope that helps.