Windows 7: Why is my signal strength poor?

Ok, recently my computer and internet was working just fine until last night. MY computer just didnt connect. So i called dell and they just fixed it right now by going into my router settings and changing a few things like changing my security to WPA Personal from WAP Open. Before I was usually getting full bars with excellent and good signal strength, but now after I fixed my internet problem, my signal strength is at poor. I tried restarting the computer but it did not work. What should I do? How can I fix it? Also, I have 2 antennas from my wireless computer and they are both parallel from the floor.

We need to know info about how far, what router, etc. BTW antenna's should be vertical

Ken

Well, I am using a wireless connection in another room separate from the room with the wired connection. The rooms are about 34-35 feet apart. And also, when I put the antennas vertical I lose all connections and windows cannot detect any networks. Here are some info about my network adaptors:

DW1525 (802.11n) WLAN PCIe Card
Microsoft Virtual WiFi Miniport Adaptor (Has yellow exclamation mark next to it)
Realtek PCIe GBE Family Controller

Also now, i cant get any connections or networks period. What do i do? What other info do you need? Also the other computer that is wired is Windoes xp and the wireless is windows 7.

Bump. Any help? Please somebody

Yellow exclamtion mark would indicate to me that thats your problem. It needs drivers maybe.
Go to device manager and select properties.That should tell you if the device is working properly.