If your webroot subscription is through msn, you can find your download by logging into the msn member center (membercenter.msn.com). If the download didn't start automatically, click the appropriate download now button for your device platform (pc, mac, or mobile). Click the downloaded file to begin the install.
You should have received an email from webroot with download instructions. Click the download button and open the saved installer file webrootpcoptimizer.exe. To begin installing webroot total protection, please log into your webroot account and download webroot total protection for your device.
If you purchased the webroot security software online, you should have received an email from webroot with download instructions.