There are much
better cards available than the HD 5450 for gaming. That's much slower than even your other two cards. For a hundred bucks, you can get one of these: http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007709%204027&IsNodeId=1&bop=And&Order=RATING&PageSize=20
I'd try that first with a clean install of the operating system.