This is Windows default behavior and a non-problem. You didn't think that when you download a file from the intenet, or double-click an executable to install a program, that the data is written directly to the folder you specified, did you? The Temp folder is necessary for Windows to function correctly, but it is both a User as well as System variable. If you don't want want the %userprofile%\Temp folder on the SSD simply edit the User Variable to point to the HDD you want it located on (which pretty much negates the whole point of using a SSD for your System drive). Instead; why don't you just run disk cleanup on a regular basis and recover the space used by temp files?
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