I just installed 2 more gigs of ram for a total of 4 gigs I started out with what I thought was 2GB kit (1GB per stick) of Super Talent T800UX2GC4 DDR2-800 PC2-6400 But it was Ampx 3AXT6400C5-2048K 2GB 2X1GB PC2-6400 DDR2-800 CL 4-4-4-12 240PIN Dual Channel Memory. But before I noticed I ordered the same 2 gig super talant kit installed it. When in properties of my computer I'am showing only 3.25 gig with all four installed. Can you mismatch c4 and c5? I went to crucials website and there scan picks up 4gb??? ran memtest for like 9 hours zero errors. Oh my motherboard is a ASUS - M2N4-SLI. please help

Windows 32bit will only see the mem. as this check in the BIOS and see what it is saying.

I am running 4gig an my Windows only sees 3.5gig different MB will see a little difference.