How do I download or reinstall my InDesign CS5 lost it when computer crashed need to install on new computer

You install exactly the same way you did the 1st time... put your disc in the drive and enter your serial number when asked

Download & Install instructions https://forums.adobe.com/thread/2003339 may help

-includes a link to go to a page to download Adobe programs if you don't have a disc or drive

-Cloud desktop http://helpx.adobe.com/creative-cloud/help/creative-cloud-desktop.html

-Cloud Getting Started https://helpx.adobe.com/creative-cloud.html

-you will need to enter your original serial number during install for non-Cloud programs

-or kglad links in reply #1 here https://forums.adobe.com/thread/2081216 may help

Also go to https://forums.adobe.com/community/creative_cloud/creative_cloud_faq