I assume your using windows ?

First of all, you got to know where your downloads are stored.
Normally this would be under:
C:\Documents and Settings\"your account name"\Shared
If it is not there, you have specified an other directory during Limewire install, and you should know where to find it.
If you can't remember, use the Limewire Library's Explore button to find it on your hard drive.
Or use the Windows search and search for a file you know is in your shared folder.

The next step depends on your antivirus programme, but in general:

Go to your shared folder , R-click it and see if there's a option to scan.
If not start your antivirus, select folders or maps and browse to your shared folder and scan from there.

And last but not least, make sure your antivirus is updated.

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Het algemeen gnutella forum in Nederlands