Use
netstumbler to check your channel used and for any other Wireless Access Points using the same.
Place your wireless router centrally and on an upper floor, If you are on a single floor place it as high as possible maybe on top of a piece of furniture.
Position your wireless router as far away as possible from devices that can cause interference with the Wi-Fi signal this includes microwave ovens, cordless phones, intercom systems, baby monitors and halogen lights.
Always change the channel used on your wireless router. Most people never change this and it results in many routers using the same channels. If you have other wireless router signals in your area, change the channel to reduce the chance that you are using the same channel as another Wi-Fi router in your area.
Try to place the wireless router in a location that minimizes the number of walls and hard surfaces (fish tanks, windows, mirrors, metal surfaces) that might interfere with the signal path before it reaches your computer.
Take a look at this useful guide at
Link Removed due to 404 Error Check your router is using the latest firmware.
let us know how it goes