Go to > Control Panel > Add Remove Programs
Go through the list of programs and remove (uninstall) anything that says "Bing", "Ask" and probably "Google Toolbar" as well. In general, I like to get rid of all Toolbar programs because I like my browsers to be clean.
You should also look for any other programs in the list which you don't need, or which look suspicious (like Shopping helper/crap, Coupon helper/crap, Buying helper/crap, etc helper/crap). If you see something you can't identify, look at the manufacturer, if it's a recognized company like MicroSoft or HP then it's probably safe (thought not always).
If you can't identify something and you are suspicious of it, just do a google search and put in "what is suspiciouspieceofcrap.exe" and see what the links say. A few links will always say it's a virus because they want to sell you a removal tool (also bogus crap), but if enough links say it's AdWare or CrapWare, then it's probably AdWare of CrapWare and you can uninstall it.
Also look for multiple copies of Anti-Viral programs and remove anything which you didn't install yourself. I usually get rid of AVG and McAfee any time I see them. Never run two different Anti-Viral agents at the same time. They will overlap each other and trigger false alerts and generally make your machine run like sh*t.
If you see Malware Bytes you can probably leave that one alone. It's usually benign and often useful.
Hope that helps.