reg export "HKLM\SOFTWARE\Classes\Wow6432Node\CLSID\{4063BE15-3B08-470D-A0D5-B37161CFFD69}" D:\qt_plug-in\qt1.reg
reg delete "HKLM\SOFTWARE\Classes\Wow6432Node\CLSID\{4063BE15-3B08-470D-A0D5-B37161CFFD69}" /f
If that doesn't get it, try these as well. Just delete and test one at a time.
reg export "HKLM\SOFTWARE\Classes\Wow6432Node\CLSID\{CB927D12-4FF7-4A9E-A169-56E4B8A75598}" D:\qt_plug-in\qt2.reg
reg delete "HKLM\SOFTWARE\Classes\Wow6432Node\CLSID\{CB927D12-4FF7-4A9E-A169-56E4B8A75598}" /f
reg export "HKLM\SOFTWARE\Classes\Wow6432Node\CLSID\{02BF25D5-8C17-4B23-BC80-D3488ABDDC6B}" D:\qt_plug-in\qt3.reg
reg delete "HKLM\SOFTWARE\Classes\Wow6432Node\CLSID\{02BF25D5-8C17-4B23-BC80-D3488ABDDC6B}" /f
reg export "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Components\3F9E7EA97A1AEE54490637032025DEF9" d:\qt_plug-in\qt4.reg
reg delete "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\S-1-5-18\Components\3F9E7EA97A1AEE54490637032025DEF9" /f
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