Computer Help, Please?

[Update: it's back to being intermittant again]

Anybody out there who could help me with my wireless Internet problems?

My laptop seems to show that it is receiving a signal from the wireless router and both the router and modem indicate they're connected to the Internet, but I keep losing access on my laptop. I've gotten "Network cable unplugged," and at other times a warning that "svchost.exe" has failed and must be restarted. Sometimes it comes back on its own after only a few seconds, someetimes disabling and re-enabling the laptop's wireless connection in the control panel helps, and sometimes restarting the entire laptop helps. But now nothing seems to work. The only way I can get Internet now is by using the direct cable connection from the wireless router.

My limited knowledge indicates it must be something with the laptop's infrared wireless device itself, but the Device Manager says everything's fine, and nothing from the built-in list of troubleshooting suggestions has worked.

Any ideas, oh Great and Knowledgeable Ones?