Just joined second life my avatar is a cloud.

[Rolig Loon]

The trouble with Google is that it remembers everything, even the old stuff that is way out of date.  You just have a simple case of bake fail, which you can solve with the methods described here .>>> http://wiki.phoenixviewer.com/fs_bake_fail

"Baking" is the process of applying surface textures to your avatar.  The avatar appearance files are all stored on Linden Lab servers, so they are applied to your avatar as you log in.  Until then, you look like a default fluffy cloud.  Baking takes a second or two, unless you have a crummy Internet connection (crummy == "unreliable", not "slow").  As that article explains, you can force the servers to download and apply the appearance files again by changing any one of the four vital components of your avatar: skin, shape, eyes, or system hair.  If that doesn't work, the chances are good that your Internet connection is more than just temporarily crummy. Get off of wireless and use a cable or DSL connection.  Then reboot both your router and your modem and restart your computer.  That should clear up all but the worst connection issues.

[Rolig Loon]

The trouble with Google is that it remembers everything, even the old stuff that is way out of date.  You just have a simple case of bake fail, which you can solve with the methods described here .>>> http://wiki.phoenixviewer.com/fs_bake_fail

"Baking" is the process of applying surface textures to your avatar.  The avatar appearance files are all stored on Linden Lab servers, so they are applied to your avatar as you log in.  Until then, you look like a default fluffy cloud.  Baking takes a second or two, unless you have a crummy Internet connection (crummy == "unreliable", not "slow").  As that article explains, you can force the servers to download and apply the appearance files again by changing any one of the four vital components of your avatar: skin, shape, eyes, or system hair.  If that doesn't work, the chances are good that your Internet connection is more than just temporarily crummy. Get off of wireless and use a cable or DSL connection.  Then reboot both your router and your modem and restart your computer.  That should clear up all but the worst connection issues.

[Lindal Kidd]

Since you've already tried the character test, we can rule out a problem with your avatar or its attachments.  The most likely culprit is your internet connection.  Pay special attention to the last four sentences of Rolig's reply.  Also, see this link for other things to check:  http://blog.nalates.net/2011/10/26/troubleshoot-your-sl-connection/

[Nalates Urriah]

Your problem is almost always a connection issue. While you may have a good general Internet connection, you may have a lousy connection to the SL servers. You can test it using the info at the link Lindal posted.

As to the wireless connection... if your gateway/modem is less than a year old and a good brand, it should be fine. You also need a newer laptop or device that can use the new wireless connection protocols. But, a lot of devices connecting to your wireless can slow it WAY down and cause packet loss, new or not. Also make sure it is secure so you don't have others using it.

A quick test is to connect via a wired connection to the gateway/modem. If it makes a difference, you have likely found the problem.