For Poser is very easy and you don't need any uninstall/install, just zip the Poser folder and unzip it at another place/disk/computer or burn a CD/DVD for backup and then delete the Poser folder.
If the size of Poser folder is bigger than 2GB or 1GB (don't remember) you cannot use zip that has size limits, compress it as rar with WinRar that has no size limits and can create multiple volumes of CD size or a single file to burn a DVD.
The compression ratio of Poser is near 40%.

Stupidity also evolves!