The MSI PM8m-V Motherboard has the Via P4M800 and Via VT8237 chipsets.
The website for MSI Does not list any drivers for Windows 7 for your motherboard. But since this is a common Via chipset you should be in luck.
A lot of driver support for VIA chips is built into Microsoft® Windows® 7 (32- and 64-bit).VIA Hyperion Pro drivers
The VIA Hyperion Pro drivers contain all of the main platform drivers for VIA chipsets. The current release of these drivers is included in Windows 7, so at this time there is no need for a VIA Hyperion Pro package that supports Windows 7. However, as updates occur, a package will be released when needed.
You shouldn't need them, but to download the VIA Hyperion PRO Drivers click on the following link:http://www.viaarena.com/Driver/VIA_HyperionPro_V524A.zip
The drivers for your video card the ASUS AH3450/HTP/256M Radeon HD 3450 AGP Card can be found here:http://www.asus.com/Graphics_Cards/AGP_A_series/AH3450DI512MD2LP/#download
If you still need further drivers for this motherboard you can go to here:http://www.via.com.tw/en/support/drivers.jsp
If you still have not found the drivers you need you can go to the MSI website and see if any of the Vista drivers will work for your system.http://us.msi.com/product/mb/PM8M-V.html#/?div=Driver&os=Vista%2064