What computer you install from shouldn't matter. The extension you're trying to install is the CB Search Bot, which allows Joomla search module to also search CB users. It is installed through Joomlas extension manager. We provide a Joomla 1.5 and Joomla 2.5/3.0 version, which can be downloaded from the Advanced downloads section. If you're having issues with other Joomla extensions aside from the ones we provide then the issue is likely with your Joomla install or server (probably tmp folder permission issue).

If multiple extensions are failing then there's certainly a problem on your site. Either with your Joomla install or with your server having bad Joomla permissions.

I suggest posting your issue to the Joomla forums or reviewing Joomlas documentation below regarding this. Please note Joomla nor us can really help you much with this as it's really a host problem.

docs.joomla.org/Why_can't_you_install_any_extensions%3F

In short it's usually due to a bad hosting configuration. Especially if you used your hosts panel to install Joomla instead of unpacking and going through Joomla installation normally.

If you don't have much configured on the site then yes I recommend doing a clean install using Joomlas normal installation method. Especially if you used an install script process from your host as such usages almost always cause wrong file/folder structure permissions.