so you have 2 desktop at hand now, it is much easier to work when you have a working and bootable cpu, even without the hardisk, you can verify which memory stick is busted by testing it to the working cpu just insert 1 memory stick one at a time and see if you can go to the cmos or bios setup. if you can go to setup with any of the memory you have then the next step is what stick makes your cpu not to boot properly, for all we know we are confusing your problem to hardware when you have a windows booting problem, so which is which