It seems zips were not extracted under one folder,
please also verify the checksum of downloaded zips

http://www.oracle.com/technetwork/oem/enterprise-manager/downloads/oem-windows64-download-1619155.html

Enterprise Manager Cloud Control 12c Release 2 (12.1.0.2) for Windows x86-64 (64-bit)
     Download the complete files
     Download      em12cr2_winx64_disk1.zip (1,527,304,174 bytes) (cksum - 3057725351)
     Download      em12cr2_winx64_disk2.zip (1,547,913,502 bytes) (cksum - 3251820480)
     Download      em12cr2_winx64_disk3.zip (2,290,032,132 bytes) (cksum - 4173962531)
     Directions
          1. All files are in the .zip format. There is an unzip utility for this platform here if you need one and we recommend you to use unzip version 6.
          2. Download the files and unzip them into the same directory.
          3. Installation guides and general Enterprise Manager documentation can be found

Can you update if the issue is solved by re-extracting the zips?

Oh .. can open an SR asap and upload the log files? Keep the env as it is so that we can look into it. Where does installer complain?
Did you also check the checksum of the downloaded zip compare it with the value mentioned on OTN site ?
Can you also check if you have all the sub-folder in the Disk1 folder ? send me the list. In 12.1.0.2 we added few fix in the installer to complain about any wrong unzip or any missing sub folders But lets check this as well.

-Akanksha

There are folders missing in your Disk1 folder. In my inhouse env i see following subfolder:

install libskgxn plugins response stage WT.zip
jdk oms Release_Notes.pdf runInstaller wls

The download is not correct.
Can you pls drop me an email akanksha.sheoran@oracle.com i need to gather more details on this OR send me the SR number.

Just today I installed 12cR2 on Windows. I think you may have unzipped the zip files in different folders. Unzip (or use Extract All as I did) each zip file one by one to for example c:\temp\em12cr2 .

Eric

Thanks for updating us.