When we writing well formatted project reports, use (i), (ii), (iii)... page numbering format for pages before the main chapters. For main chapters we use kind of 1, 2, 3... formats. There are few steps to manage this page numberings for different parts.
Steps for MS Office 2007
Lets think we need to add (i), (ii), (iii)... page numbering format for first 5 pages and 1, 2, 3... page numbering format for rest of the doc.
Step1: Goto page 5 click on that page (Lets think the doc start at page 1, not 0)
Step2: Page Layout tab -> Breaks (in the Page Setup section) -> Section Break -> Next Page
This will start a new new section and it start at page 6.
Step3: Goto any page in first section (page1 - page5) and click on it.
Step4 : Insert tab -> Page Number (in the Header Footer section) -> Format Page Numbers...
-> Choose i, ii, iii.... number format (in the Page Number Format dialog box) -> Ok
Step5: Do the same above steps to set page numbers to next section with selecting the 1, 2, 3...