Wireless adaptar speed all over the place? quick question

Try changing channel, especially if you can detect neighbouring wifis -- select channel at least 3 channels away from strongest neighbour. Relocate video sender or cordless phone base away from computer or router.

If it's not interference it will be a reception problem. Test with computer in same room as router -- try raising the router above furniture level.

User your wireless adapter's scan facility to detect for neighbouring wifi and note what channels are in use.

Have a look at the manual for your router -- generally you log in to the router user interface via your browser (usual address is 192.168.0.1 or similar -- you can check the address using IPCONFIG /ALL from a command line box in Windows).

Once in router user interface select a channel a few stops from strongest neighbour.