How do I build a new wall in my garage?

I know who to build a wall, but what is the best way to secure it to the floor?

Since you know the wall is not going up or down, all the anchor needs to do is keep the bottom plate from moving in and out. Almost any of the options mentioned will accomplish this. Drilling and installing screw sleeve anchors will work but is overkill. Renting a powder actuated nailer will work but is no more effective than fluted masonry nails and a hammer, at a substantial cost difference. You can use a drill and tapcons if you feel thats the better option. Me personally, I'd go with the 2" fluted masonry nails and hammer. 1/2" penetration, every other stud bay is more than adequate and cost efficient for this job. I prefer the fluted masonry nails over cut nails because they are much easier to drive and less likely to bend over. If this was a basement remodel with multiple walls to secure, then I'd be inclined to recommend the powder actuated nailer (for speed, as it is actually harder on the wrist then a hammer).

edit: For the guy that said, "hammer it in at an angle", thats not the correct advice. Straight down is the best. If you drive at an angle, the nail can ride along the surface of the concrete, not penetrating at all. Or, seem like it penetrated but in reality, just caused the surface to chip away.

Hilti Gun. You should be able to rent one for a one time project.

nails shot with a 22cal nail driver.

Rent a hammer drill to drill through the 2x4 and into the floor.Buy cement screws to secure it to the floor. Or you can buy cement nails and nail it directly through the 2x4 into the cement, but nail it in at an angle it is easier to get into the cement. Hope this helps