Moved to VirusScan Enterprise from getting Started for better attention.
Manual downloads are here: http://www.mcafee.com/apps/downloads/security-updates/security-updates.aspx?regi on=us
I'm not an expert in Enterprise however, so hopefully someone will be along soon that knows more about it.
From the link provided by Ex_Brit download the superdat and transfer it to your usb device.
The superdat will update the DATs and the engine to the latest versions. The superdat executable is updated on a daily basis to reflect the latest dat release.
Whilst your on the website you might as well pick up patch 5 for 8.7 if you have a grant number (depends on how your copy is licensed)
If the computer is networked at all, you could point to a computer that does have internet access and VSE installed.
In doing so, you would be using the updates received by the second machine to update the computer without internet access.
Open the VirusScan Console
Click Tools, Edit AutoUpdate Repository List.
Select the UNC repository and click Edit