Be aware that Aida32 and similar programs may not show you "exactly" what's in your box. The only way to be sure is to actually get the identity off the mainboard itself, together with any revision number.
Aida32 will show you what to look for!
Basically, mainboard ID's nowadays are much easier to find than in the past. They might have the manufacturers name printed on the board, or their abbreviation. There will also be an aplha-numerical code giving hints as to the chipset used.
For example:
SL-75FRN2-L ..... is Soltek nForce2 Ultra 400 chipset with onboard LAN........... nVidia nForce2 chipsets are AMD specific. This chipset supports 400mhz FSB processors.
A7V8X ..... is an ASUS motherboard sporting the Via KT400 chipset and 8x AGP standard. Despite it's name, it was designed to run AMD XP CPU's on a 333mhz Front Side Bus speed and not the later 400mhz ones. It does support PC3200 - 400mhz ram modules.