If your current version is ALM-PC 12.55, you will need to uninstall the ALM software and install the ALM 12.60 software. You do not have to uninstall the Performance Center software if you have Performance Center software version 12.55.

For the ALM Server, Micro Focus states the following from the Installation and Upgrade Guide on Chapter 11, page 66:

''It is strongly recommended that you not use any of the existing components as part
of the new system. To install the new version of the ALM server on the same machine where the existing ALM server is installed, first reformat or reinstall the machine's operating system. you can also uninstall the old version of ALM. '' Please see the link below:
https://admhelp.microfocus.com/alm/en/12.60/pdfs/Install_Windows.pdf

For the PC Server, Micro Focus states the following from the PC Server Installation Guide on Chapter 2, page 32 states the following:

''Uninstall any previous installations of Performance Center Server if earlier than 12.50, and Performance Center hosts if earlier than 12.55 from the machine. Note: For Performance Center Server 12.50 and later and Performance Center hosts 12.55 and later, you can upgrade to 12.60 without having to uninstall the previous version. '' Please see the link below:
https://admhelp.microfocus.com/pc/en/12.60/pdfs/PC_Install.pdf

It is very important to review the ALM-PC installation guide(s) and have a full understanding of the upgrade process as this is a complex process.