Thanks for your help with my question yesterday, all I need to know now is; I got 4MB (2x2) as an upgrade as the sites I looked on said that's what the laptop (Toshiba Satellite Pro A120) would take, when I put them in all I get are the flashing lights to say there's a memory problem - tried both, one in one slot, then the other, original memory plus one new, both new, left foot in, left foot out, everything.
Tried one of those sites that scans your computer and, according to that the machine will only take a total of 2GB (one in each slot, obviously) - so, basically, would I get the flashing lights showing an error if I had too much memory on board?