Okay, I'm pretty sure that it is not possible for Ubuntu to cause hardware problems with Windows but..
I installed 12.04 as a dual boot on a Compaq Presario CQ61 running Windows 7 Home premium. Install ran flawlessly and dual boot works fine. Like many other people, I noticed my machine ran very hot when using Ubuntu. Weird part is it now also seems to be running hotter when I'm in Windows. Common sense and what little I know about computers tells me that there couldn't possibly be a connection but I want to check with the community just in case.
Thanks in advance.