ChemDraw: ChemOffice/ChemDraw installer thinks ChemOffice/ChemDraw is already installed. How do I address this problem

The ChemOffice/ChemDraw installer thinks ChemOffice/ChemDraw is already installed. How do I address this problem?

Please try the following steps as a workaround to install ChemOffice/ChemDraw (eg. v20.x) on your Windows 10 machine.
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1. Move the downloaded installer (cos20.x.exe) to your Desktop and create a new folder on your Desktop with the name COS20x..
2. Right-click the installer (cos20.x.exe) and select “Run as Administrator” from the context menu..
3. The wizard asks you to point to the folder where you need to place the extracted installer, select the browse button and point to the COS20x folder and click the OK button..
4. After extraction completes, close the wizard and open the COS20x folder present on your Desktop and browse to the \PerkinElmer\ChemOffice folder and run the following installers one by one..
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PerkinElmer_ChemOffice_Suite_2020.msi.
PerkinElmer_ChemOffice_64-bit_Support_20.1.1.msi.
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After completing the installation, browse to \PerkinElmer\ChemScript folder and run the following installer:.
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PerkinElmer_ChemScript_20.1.1.msi (for 32 bit MS Office).
or.
PerkinElmer_ChemScript_20.1.1_x64.msi (for 64 bit MS Office).
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[ You can determine the version of MS Office (32 bit or 64 bit) in the following way:.
1. Launch Word and open a New Word document then select "Account" from the File menu.
2. Then click on the "About Word" button. You will find the exact version information as well as the 32-bit or 64-bit version.].
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For the first launch of ChemDraw 20.x, use right-click and Run as Admin..
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If you got the "Software Activation" window, enter your name, email account and copy/paste the activation code in the activation code text box. Then click the "Activate" button..