It's also proof that the cause is too many things. I can't tell from your post what it is this time but tell more about the post move driver work. Microsoft does not do drivers well enough so let's hear more about post move work.
Although I'm not quite sure that this comes under this section, windows explorer has been taking up around 30 - 35% of my CPU's processing capacity. it started just after I replaced the broken MSI GD-45 gaming motherboard with the MSI gaming 7 motherboard, whilst doing this I swapped my I5 - 4670 with my brothers I5 - 4670K. minus this problem my system took well to the change informing me that my processor ad changed and directing me to the bios to view any new settings that may have come with the change. After boating up installing the new motherboard drivers and checking everything was fine i added a 600 MHz overclock to the processor which appears to be stable after stress testing it for an hour or so. About a day after the overclock I realized i had this issue. I've run antivirus software, booted in safe mode, in which the problem no longer seemed to persist but when i re-enabled start up items (1 by 1) non seem to cause the problem again until about 30 - 40 minutes into my computer being turned on with all enabled (I should note that this normally occurs as soon as i startup and not after a specific program launches.). short of reinstalling windows, which for me goes XP, upgrade to 7 then upgrade to win 10 i cant think what to do.
I apologies for the very long post but i wanted to be sure none of these little details or a combination of them were responsible for my problem. thank you if you read to the end.