Who did you pay for LW? Basic is free & Pro costs $18.88 USD for 6 months of updates & email support. When you buy Pro, you recieve a link to your personal download page...you can use that to download as many installers as you want Likewise, you can download the free basic version again & again!
The only official site for downloading either version is www.limewire.com

Try redownloading the installer using a different browser. Also, are you using any antispyware programs? If so, disable them while you download the installer (some antispyware wrongly picks LW as a threat & can stop it working properly).