I bought a MacBook Pro earlier this year (Early 2011 model), with i7 and 4GB RAM (2 x 2GB). This was to be used as my work computer, running Windows 7 most of the time. This setup has worked great and I had no troubles using the Windows-on-Apple approach.
Rather than buy the expensive 8GB upgrade from Apple at the time, I decided I would upgrade the RAM later, when memory became a problem.
So yesterday that time came, and I bought 2 x 4GB dimms (Hynix PC3-10600S 1333mhz DDR3 204pin) to replace the original RAM. and carefully installed these myself. The new RAM is the exact same brand and configuration as the original RAM, except twice the capacity -- bought from a reputable Apple supplier.
After the installation, Mac OS X seems to work perfectly.
Windows 7, on the other hand, BSODs within two minutes of startup... every time. Any programs that I manage to run crash within seconds, and eventually this results in a BSOD (either IRQ not less or equal, or page fault).
Any ideas why more memory would work in Mac, but fail in Windows?
(I've since changed back to the original RAM, and this works fine in both OSs).