If you want FDM to download files one by one, set the maximum number of running downloads to 1 in Settings | Downloads | Network, or click <a href='10'>here</a>.
If you are experiencing slow downloads, try <a href='http://www.freedownloadmanager.org/fromfdm.php?link=2'>updating your network card driver</a>.
When you delete a download in FDM, it goes to FDM's Recycle Bin. Use Shift+Del key combination to bypass the Bin and remove the download completely.
In case you download software you also need to <a href='http://www.freedownloadmanager.org/fromfdm.php?link=1'>check your registry for errors</a> to prevent computer slowdown. We recommend this <a href='http://www.freedownloadmanager.org/fromfdm.php?link=1'>free scanner</a>.
You can use macros to define destination folders for your downloads to organize them better. See group properties.
The use of a proxy can decrease the download speed. Try disabling the proxy in FDM in such cases.