I have a Compaq Presario SR5610F with an upgraded power supply (Antek 500 watt) and Vista 32 bit. I purchased an ALFA 802.11 b/g usb network adapter which is based on the Realtek RTL8187L Chipset. Here's the problem. When I plug the adapter into the USB port (doesn't matter which one) and load the drivers, the adapter just cycles on and off. Meaning it appears and disappears on the computer constantly at a rate of about once per second.

If you have the device manager open, it appears and disappears under network adapters. I've tried every driver I can find.

I even let windows choose the driver from Windows update. I did a complete system restore (using a different hard drive) back to factory new condition. Made no difference. Tried a different adapter, did the same thing. Is there some sort of incompatibility with this presario and the 8187 chipset? HI, wrote: I've tried the latest drivers from Realtek as well. I've tried a total of 17 different drivers.

Awus036n of the wireless network adapters listed on the page from the hyperlink above were released a few years back making it difficult to purchase because alfa network awus036h power control normally releases new products very frequently and phase out the old versions.

New ones, old ones, XP drivers, Vista drivers, win7 drivers. The ones that will load on my system all have the same effect. Apogee aw9101 b200p drajver. The constant cycling on and off about once a second. Have you tested the ports on your desktop with a mouse or a keyboard? Use a simple USB devivce.

Try testing the USB network adapter on another PC with the same operating system. The problem will be the device itself if you have tested the ports and the ports are working.This is all about isolatioon to find a root cause. Best regards, erico. ImaginaryKaos wrote:The ports are working properly. My keyboard and mouse are both USB. I have a Linksys USB adapter that works just fine in any of the ports. It seems to be some sort of incompatibility with the Realek chipset and/or drivers.

The 'cycling' effect does not occur until after the drivers are loaded. If you plug the device in without any drivers loaded, it doesn't cycle on and off. Hello ImaginaryKaos, It appears you may have a defective product. Here are the specifications listed for this device. ALFA 802.11g wireless USB adapter. Includes a 5dBi Rubber Duck Antenna.

The adapter comes with an RP-SMA antenna connector so that you can add an external antenna to boost your wireless range and signal. And to make things better we are including a dBi gain rubber duck antenna in the sale (comes with the adapter in the retail box). The high power 1000mW can increase the receive signal range and the dBi antenna can increase the signal strength. So if you are looking for a device to connect to an indoor / outdoor wireless signal. This is your perfect solution. Features: Plug-and-Play Compatible with windows 98SE, 2000, Millennium, XP, Vista, and Linux - Now works with Windows 7 just ask us for the Link. HIi wrote: I could understand if one of these adapters produced this problem, but three of them?