Your laptop will probably work if it's new enough, but you will then lose the ability to run Windows directly on your laptop hardware. If you choose to use your laptop, backup the data on th laptop and burn the iso image fo ESX 5 to disc. Then, put the ESX disk in your laptop and boot up. You will blow away Windows in the process, but you might have an ESX server when you are finished. I say might because VMWare doesn't directly support laptops.
Since you said you were studying for the exam, I would recommend you buy a dedicated VM server. You can then install vSphere client on your laptop and access your dedicated server.
If your budget permits, pick up a Dell PowerEdge 1950 off ebay for around $200. Put at least 16 GB of memory in it. I added a 1 TB SATA hard drive to mine. Other brands of servers will work too, but the Dell PE 1950 was the least expensive way (that would run ESXi 5.0) I found to go about it when I began studying for my VCP. HP's work good too, but then you get into generation specifiic issues... for example, a DL380 G3 won't run ESX 5.0 but a DL380 G7 will. They are still the same machine, but different versions. It gets confusing. That's why I stuck with Dell.
I now have ESXi 5.0 installed on the hardware, then inside of that I'm running (2) ESX 4.0 servers and a Windows 2008 Server for vSphere.