Is this the problematic adapter - D-Link DWA-552 XtremeN Desktop? I assume the issue is wireles connection?
You might want to download the most recent driver for it, here's the link
to the D-Link site.
Install and run http://www.xirrus.com/Products/Wi-Fi-Inspector.aspx
Double click the Xirrus Icon on your Desktop, Tap the Printscreen key on your keyboard, open up Paint then choose Edit from the Menu and select Paste, then SAVE it. Upload and attached the file on your next post.