Hard drive has no effect on your framerates or level of detail you can set. Laptops can't handle games usually by default.
One possible scenario however is that when geek squad replaced your harddrive they failed to properly install device drivers. If your graphics adapter driver is not installed your performance will be horrible.
Not to mention your other motherboard related drivers. I've seen many kinds of hard drive replacements, and done numerous of them myself in various ways. If your old hard drive was in poor condition and they still just cloned it to a new one, it is quite possible that there are severe failures in the Windows files. The reason to do a clone instead of a clean install is to
- a) try to save your valuable data as is, leaving the responsibility of doing backups to you, and
- b) try to save the reinstall partition for you to be used after you've done the abovementioned backup,
because of course you never bothered to make the factory default installation disks despite all the nag screens that popped up at every boot...
I've also seen that many repair shop workers don't actually know there's a reinstall partition on almost every laptop and brand desktop, too. The task, being quite simple, is often given to the intern without any further advice. They use a generic installation disk and try to find the drivers that aren't included in Windows from various and often questionable sources. One of the most frightening scenarious was when I found out that a nationwide pharmacy chain had a Community Toolbar installed in the machines they had got downgraded and ready installed from their headquarters. Apparently the person who had done the downgrading, instead of using the HP website, had used some adware to find the drivers needed.
So back to your framerate problem, if after the hard disk replacement all your files were as the used to be, a clean reinstall might help.