Do you have a firewall? 'Cause that's basically what the pop-up is saying.

Try disabling it from the taskbar.

Q: Every time I click the LimeWire icon to open it, I get the error "LimeWire was unable to initialize and start. . ." What does this mean?

A: Some security programs block loopback connections for all programs on your computer unless an exception has been created within the security program. If you are running Norton Antivirus, look for the Internet Worm Protection feature, and add LimeWire to the list of exceptions in that section.

http://www.limewire.org/wiki/index.php?tit..._Questions#sta4

What firewall/anti-virus program do you have anyways?
Create an exception for LimeWire.

How do I create an exception for Google Earth in McAfee Personal Firewall?

If you have the McAfee Personal Firewall (also McAfee Internet Security Suite) software installed on your machine, this program may be blocking Google Earth's access to our servers. To create an exception for Google Earth in the program, please follow these steps:

1. Open Google Earth and try logging in.
2. Open McAfee Personal Firewall Plus
Start -> All Programs -> McAfee -> McAfee Personal Firewall Plus
3. Click on "Internet Applications" in the left column.
4. Scroll down and select the "Google Earth" entry.
5. In the "Permissions" column it needs to say "Allow Full Access".
6. If it does not say that, press the button on the bottom right that says "Allow Full Access", verify it's changed using last step.

Do you know how to?
This is for Google Earth, but it would work the same way.

Just replace everything that says Google Earth with LimeWire.