I downloaded the trial for DB2 10.5 for windows x64. Unfortunately I cannot install only the workgroup server edition, DB2 Express, Data Server Client and Connect server, the "Install New" and "Work with Existing" buttons of the other products are not visible.
I have windows 7 ultimate x64 SP1 installed with 8GB ram. According to the DB2 requirements that should be ok.
Currently I have a trial of DB2 LUW 9.7 sp7 x64 advanced enterprise server edition installed. I tried deinstalling it with the hope the 10.5 install would work, but to no avail.