.tpm files default to C:/

I've been trying to install an update to a new Quicken program. I've worked with Quicken support till there is nothing left to try on that end, they gave me new copies of everything to make sure nothing was corrupt. The software installs with no problem. The update puts several .tmp files in C:/, which I'm told Windows 8.1 isn't suppose to allow. When the update runs it fails with the following error:

----- Processing Patch File -----
Creating New System using Temporary Files
Patching: Qsapi\qsapi_plan.DAT .......... Applying ADD File Patch for 'Qsapi\qsapi_plan.DAT'
Adding New File
error ept0018:
RTPatch error ept0018: Failure Opening New File: PATCH was unable to open the named file. It was attempting to open this file to create a file for the updated version of the system. This can be caused by a disk or network error or if a directory exists b
Failure Opening New File: C:\QuiC0AC.tmp\qsapi_plan.DAT

RTPatchApply32 returned 18
ERROR: Error occurred applying patch to Quicken directory.
Unloading RTPatch Engine.
Deleting temporary directories...
Deleting directory C:\QuiC0AD.tmp : Failed
Deleting directory C:\QuiC0AE.tmp : Failed
Deleting directory C:\QuiC0AC.tmp : Failed
Not Rebasing DLLS
Displaying Wizard 5

UPDATE FAILURE REASON: ERROR: One or more error(s) occurred with the patching engine, or patch data files.

I was told to verify the following settings and did so.
Environment variables - Under variable - TMP and TEMP are set to %USERPROFILE%\AppData\Local\Temp
System variables - TMP and TEMP should be set to %SystemRoot%\TEMP

I managed to get the tmp files deleted, not exactly easy, but it didn't help.

I created a new Windows user account and installed the software and update, it failed again.
I installed the software and update on my laptop with Windows 8 with no problem, so it appears to be a problem with my desktop with Windows 8.1.

I've used Quicken for several years on this same computer with no problems installing, upgrading or updating.
I'm not one to change any kind of settings on my computer, everything is pretty much default.

Can anyone tell me why this is happening and if it can be fixed?