My yard needs some serious help

[foci03]

My grass has a number of problems. I've tried using some fertilizers before but so far I haven't seen much of a result. I mostly have two different kind of week in my yard. The first is a leafy, green weed. The second is a heavy looking green grass, but thicker than the rest of the grass. Most of my yard seems to be covered in it. I would like to try and replace the weeds and recover my lawn. Any suggestions would be very welcome.

[foci03]

This is another picture of the thicker, greener looking weeds that look like grass, but not sure what it is.

[BirdLover]

There is more than one way to fix up your lawn. If you can afford to replace it with new sod, that is one way. The old dirt needs to be removed first. Expensive and labor intensive.
Some things that benefit existing lawns are thatching, aerating, compost, reseeding. I'm not a lawn expert, however. Lawns look great at first and require high maintenance to keep them looking nice. One a lawn is neglected, it is hard to get it back to looking good. You might want to try the library. They probably have some good books on lawn care. I don't care for lawns myself because they require so much maintenance to keep them looking nice. I'm replacing mine with lawn alternatives and gardens.

[Sharky169]

if the thick grass grows faster than the rest it might be barn grass or field grass nothing targets just that you'll have to spray it with round up. over seed in the fall and spray weed killer in the spring. Feed and Water your lawn regularly or don't bother doing anything

[imafan26]

lawns should be renovated every seven years, but people rarely do that. Over time the ground compacts, weeds invade, grass gets mowed but not aerated top dressed or fertilized.

I think it is time to renovate.
http://www.ext.colostate.edu/pubs/garden/07241.html