Why do my knees hurt when I do lunges and squats?

Hi,
Have you ever had a knee injury before? This could be a major reason why you have knee pain. Also, you could have had a knee injury and thought it was healed when in reality, your body just began to work differently because we NEED our knees and you had to use it so you just started compensating elsewhere, so now when you are forced to use your knee, your body can't compensate anywhere because its full impact on your knee. There could be some scar tissue, or it could be healing.
Perhaps, its not even from an injury though - maybe your knee just is not used to the strain that you are putting on it. lunges and squats are two of the highest impact exercises on the knees. In this program you are doing, do you HAVE to do both lunges and squats EVERY day? can you do other types of exercises instead of those two every other day to give your knee a break? Also, what kind of shoes are you wearing when working out? I know you mentioned you are on your carpet which could be better than directly on the floor, but it also depends on what is under the carpet - cement, wood, tile etc. Try wearing a shoe with a good support structure in it.
If you need to do those exercises every day, then I would invest in something like a medicine ball and you can put that up against the wall and lean into that as you do a squat. Although you are not working as hard, you are taking some of the stress off your knees. As far as squats go, I would really recommend not doing them if your knees feel as close to injury as you make it sound.
Your body knows itself very well - it won't be giving you those signals for no reason. If you feel as if you are going to have an injury, then STOP! Find something else to do until your knees can build up to the impact and intensity that are required of them for that specific exercise program. It's not worth it to push and push and then lose the use of a knee or not be able to do certain things in the future because you weren't listening to your body.
Take it from me - someone who didn't listen to her body and now reaps the consequences of it daily. It can be worked around, but my knees will never be the same because i listened to stupid coaches who told me to push through the pain and I continued to push hard.
Hopefully this is helpful to you!

If my form Isn't 100%, my knees let me know right away. Really feel like you are sitting back into it and get your weight back more on your heels. You should be able to wiggle your toes because they bear almost no weight.

Don't push it, knee damage is almost irreparable.
I would love to be able to do those things, but I'd end up in one of those commercials "Help! I've fallen and I cant get up!"

I would agree with the rest, it could be your form. You should look up Youtube videos of people squatting and make sure you understand the form you're supposed to be in. Also, what I did was just squat the barbell for a week or so until I was comfortable enough with my form to start adding on weight. That might be something that you could do too. And it's worth it to be sure you're not going to hurt yourself, even if it does set you back in your program a little.

Read it more closely, I guess you aren't doing weighted squats. But, still, look up videos of people doing squats and try to perfect your form anyway.

If my form Isn't 100%, my knees let me know right away. Really feel like you are sitting back into it and get your weight back more on your heels. You should be able to wiggle your toes because they bear almost no weight.

As someone who struggled to get form right on squats/lunges for a while, this was the trick that did it for me. As soon as I think about needing to be able to wiggle my toes, I felt the weight shift to my heels. At the time I had thought my form was okay, but I could certainly feel the difference when I wiggled my toes. Works the muscles far better and doesn't hurt the knees!

I agree with the other people questioning your form. The only way I feel comfortable doing squats and lunges is usually with a wall mirror so I can see how I'm positioning myself. There have been times where I tried to do a lunge and it just felt weird or uncomfortable and then I'd know I was positioning myself incorrectly.

Sorry to say this but the fluid that cushions our joints starts to depleted as we get older...:sad:

I am just finishing up the same series and I found 2 things changed how my knees felt...form, watch your form. And shoes, I was wearing totally inappropriate sneakers for what I was doing, they nearly killed me. Do some knee stabalizing excercises as well, see if that helps