Acrobat XI Pro Install Error "Not enough memory resources are available to process this command"

People from Adobe don't send you messages, especially about old unsupported versions. But scammers do, offering email support, "reduced price upgrades", offering to sign into your computer to take a look (what harm could a scammer do there...)? Be careful.

Acrobat XI is an old and unsupported version, and is no longer compatible with Windows 10, or 11, so problems are to be expected. To increase the chances of it working properly make sure you have all updates installed (up to 11.0.23) and run it in Compatibility Mode with an earlier OS, like Windows 7.

Updates are available here:
ftp://ftp.adobe.com/pub/adobe/acrobat/win/11.x/
You must use a dedicated FTP client to open the link, it won't work in most browsers.