Why does my home page keep going back to /?rs1 after the Yahoo.com settings?

Answer 1

Because you have a spyware, more specifically a hijacker.

Getting rid of it may be fairly complex. Start by doing an online scan on http://housecall.trendmicro.com which will clean most of it (for free of course).

Then if the problem persists, restart your computer in safe mode (press F8 continuously just before windows logo appears on startup) and reset your Internet Explorer settings. To do so you...
- go in the tools menu->Internet Options
- click on the Programs tab, press the button that says Reset Web settings and confirm by clicking Yes
- go on the Advanced tab, press the button Restore Defaults
- in the same screen, in the big list, locate the browsing section and then look for "Enable third party browser extensions" and uncheck it

Then restart your computer in safe mode with networking support, go back to http://housecall.trendmicro.com to remove some more junk.

If you use Windows XP, I strongly encourage you to install Windows Defender which is free from Microsoft. You can get it at http://www.microsoft.com/downloads/details.aspx?FamilyId=435BFCE7-DA2B-4A6A-AFA4-F7F14E605A0D&displaylang=en . It may help you resolve your current issues but the main reason to use it is that it will block a LOT of settings from being changed without your knowledge.

Once all this is done, if you still have issues, you will need to verify your running processes either trough the task manager or through Windows Defender (Control Panel->Software Explorers).