I am a beginner administrator for my own Win 2008 R2 server. In the last 2 weeks, I noticed that the workstations internet access has gotten slower and sometimes does not connect to the net. It also got slower trying to connect to the server via RDP and Outlook Web Access. Now, it has gotten so bad that there is no access, except for every couple of hours I can get some very slow access to the net.
I tried clearing the DNS cache and it works (back to normal speed) for maybe an hour. Then it's back to supper slow or no internet. The speed of our LAN seems normal. The ISP has done testing and says it's not on their side.
Please help a beginner.