Trouble Browsing

Due to some dumb-ass software my retarded weirdo sister downloaded onto my computer, every page I close is automatically returned when I open it back up. At first it didn't ignore me, but now it is really starting to get on my nerves because of the sheer inconvenience. The program downloaded was MyWebSearch (evil).

Any idea how to disable this shit? I'm using newest version of Mozilla Firefox.

Get mbam:
http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html

Download, install, UPDATE IT FIRST...
Perform a quick scan, no need of full scan for this one.
Delete all what it has found.

By then, get hjt:
http://download.cnet.com/Trend-Micro-HijackThis/3000-8022_4-10227353.html

Scan with a log file, a notepad will pop up, copy all what's in there and paste here... I'll check out what's left that could be wrong...

Also, add spybot to that list

Hehe no need in this case with that infection...
But yeah it's recommended to protect your computer though...
Spybot is good at protecting your registry and all, because of its "resident" tea-timer which will prevent any change done to your registry... But when it comes to spotting infections, it didn't spot most of my crew's created spywares... Worse of course with sneaky viruses, worms etc...
That still leaves to other protections needed (and unprovided by spybot) like the files you download... Spybot wouldn't spot infected downloaded files like AVG or Avast or few other free anti-virus would do...
I tried to create a sneaky virus through vbscript and I wasn't even half done with it and Avast killed it...

Malwarebytes is a great exterminator though... Ideal if you already got infected haha...
By then, this is why I request the hjt log... Perhaps after seeing that hjt log, I may need a dds log or recommending combofix along with its log.

A lot of infections can only be exterminated by the help of a security expert... which is where I've been specializing myself in the past...

For Win cleaning, I use ESET NOD32 Smart Security, Ad-aware Pro, Spybot and MBAM. There are some viruses that cannot be cleaned using any of these tools, if they got deep into system files (from the public ones, Win32.Agent and Brontok are my favs). Do not use Internet Explorer, switch to Firefox (most features) / Opera (faster than FF) / Chrome (faster) / Midori (fastest, but still in testing phase).
Try these tools out. If you have to reinstall, I recommend a slipstreamed version of XP SP3 with less services on (MicroXP) and updated NOD32 on top of that right after installation. Vista and Seven are not needed for new programs other than games with DirectX 10 (they have DX9 mode and OpenGL is better anyway).
Windows is a playground, since it's needed for gamers and hackers alike.

I also use ESET NOD32 (paid licence) and I would recommend it to everyone.