Updated: October 19, 2012
Before we begin - this article does not promise a 100% solution, only a handful of workarounds that will help you enjoy Skype without having to uninstall it. I wanted to make this clear upfront to avoid minutes of frustrating and misleading reading. Now, that we know we are going to be enjoying a less-than-perfect solution to Skype's most annoying features, let's move on.
From the technological perspective, Skype is a decent program. From the user experience perspective, it is a bothersome, lowly product that is designed to cram advertisements down your throat. It started as a decent IM client with encryption, good audio and, later on, video collaboration. Then, it turned into a social network crapfest. And it started serving ads to you, day and night, inside your very call windows. So the question is, how do you restore Skype to some basic sanity without having to purge it away from your box?
Best solution: Linux
Believe it or not, Microsoft has recently released version 4 of Skype for Linux. It is drastically better than the Windows version, and it comes crap-free - no Home screen and no stupid advertisements. If you can afford, you might want to use this option. This is the only 100% effective way of getting rid of the nonsense.
Alternative: Get rid of Skype 5.X
On Windows, the crapfest started with the release of the major version 5, which you may want to uninstall. Please note that you cannot use the Skype installers for that purpose, even if you've kept them safely saved somewhere. The installer will always pull the latest version or fail to do so at all.
However, you can grab older, full version from oldapps.com and install them as you fit. Make sure that your Windows version supports the application and that there are no incompatibility problems or crashes. If you're worried about security, then make sure you do not accept strange links from strange people, and you'll be fine.
Make Home screen go away
There are several methods to making this happen. One, you should first switch to Classic View mode, which separates your contacts window from the Home screen window. Then, close the Home screen window. Quit Skype. It is as simple as that.
However, if for some reason, this does not work for you, you may want to consider using a custom startup method for Skype, which will also kill the Home screen window after it's been launched. This requires putting up a few commands together into a batch file.
START C:\"Program Files (x86)"\Skype\Phone\Skype.exe ->
-> /minimized /legacylogin
CMDOW "Skype Home" /CLS
Notice the arrow mark denotes a single line split over in the output. Anyhow, running these commands will fire up Skype minimized using the legacy login option. After a timeout of five seconds, the Skype Home window will be closed. You might need to change the timeout value to a higher number if your machine is slow and takes time launching Skype, because you need the Skype Home active before you can close it.
This is explained in more detailed in this lovely post, with some variation of the use of the timeout function. The original method uses ping to localhost, while I think the timeout is cleaner. Another option is this little program - use with caution.
Someone also suggested this - not sure, untested, your at your own discretion.
There's also WMIC for controlling Windows programs.
Remove Skype ads
The second menace are the inferior Skype ads. They show up in the Skype screen as well as in your call windows. Intrusive and useless. For example, Skype likes to think that since I live where I live, I might be inclined to buy the same cars that the rest of the mediocre population goes for, mostly lowest-of-the-low brands with automatic gearbox. Screw you, I want German cars with six-speed manual.
Then, when you open call windows and the call starts, you get more ads there, mostly an invitation to join Skype premium ad-free service, which means they will be now molesting you with lube.
Anyhow, how you do it - you change the language. Skype bases your ads on your language. So if you change your language to a non-existent one, Skype will not be able to load the relevant ads.
So what you need to do is click Tools > Change Language. Then, toward the bottom, select Edit Skype Language. This will open the Language File editor. Click Save as and name your file anything you want, like: I do not want ads. Then, load this language using the same path like before, Tools > Change Language. Restart Skype. Should come up ad-free. The only caveat is that language edit will default the echo calling service and such to wherever you live rather than the chosen default language. But a small price to pay for hassle-free usage.
Minimize your chat window
Another good thing to do is - minimize your call/chat windows to a minimum. Most ads are too big to display in this space, so they will not show up. This is another layer you can use in getting rid of crap.
You can also block Skype ad networks in your hosts file or your firewall, but this is an advanced step and will affect every program that tries to communicate with said services or websites, for good or worse. I would recommend you explore this venue last.
One more thing
What you can also do is every time Skype pops an ad on you, go to the Skype website, login and then write a ticket to their support complaining about this intrusive use of advertisement and how it bothers you. Let your voice be heard. Do not suffer in silence just because they offer a free product. There are tons of companies that offer free products but do not assume your sphincter is a bullseye target.
And after all this, similar to what I experienced with my Android phone, here's what I have to say to Facebook integration in Home screen and offering me shitty automatic-gearbox cars in your stupid ads:
You can always search in your favorite search engine for tips on how to get rid of the Home screen and ads. You will be flooded with Skype forum posts, including some threads running hundreds of pages long. Here's a sampling:
As best compilation as I could come up with, do not hate me if it does not work for you as expected, I did not promise a miracle. It is a rarity when you find a program so stubborn, so pervasive like Skype. Really, really crap when you think about it. If your clueless, non-techie friends weren't so dependent on it, you would be able to migrate them to something else. As it is, you must use this program to talk to people who haven't heard of any other software for instant messaging and calls.
This article teaches how to disable Home Screen using several methods and then also get rid of the ads. There's a combination of Linux, older Skype versions, simple options in the menu, some command-line use and scripting, editing configurations and languages, even firewall rules, if you must. However, at the end of the day, you might be satisfied.
I hope I've helped, and the moment I find a mass-suitable IM/call program that does not treat its users as a proverbial toilet bowl, I will let you know.