You can not mess up your laptop unless you download stuff from an unknown source.
First off we need to make sure a recovery is on the phone...
go here
ClockworkMod ROM Manager - Recoveries and download the google galaxy nexus (what ever model you have (att and Tmobile are gsm)
then you need to download the SDK package from google. here
Android SDK | Android Developers
then once it downloads... you will need to unzip it. Put all the files/folders into a new folder on your C:/ drive and name it android.
then you will need to navigate through the folder and find the one that has some files that say fastboot and adb.
right click in here and say open command promt here.
This will open a black box that allows you to communicate with the phone. (cmd, terminal)
then plug the phone in and see if the computer can recognize it. If not you will need to download the drivers. Install Keis from samsung and it should fix that
SAMSUNG KIES
then you will need to connect the phone and type adb devices in the black box. if it shows the phone its working. Now you will need to push the recovery to the phone.
place the CWM recovery file from earlier into the same folder where it says fastboot and adb.
then type fastboot flash recovery recovery.img
it should push it to the phone. If it works it will take around 3 seconds.
then go to the phone and hold down power and volume down until a screen pops up with an arrow. Use the volume down button until it says recovery. then click the power button.
once in here your phone will be fine. you will have to choose a ROM from XDA-developers.com I prefer purity
[ROM] [4.2.2][GPL][GCC 4.8.1][Linaro] ♦ | Galaxy Nexus > XDA
then navigate on the phone in recovery to mount your device. Once mounted. You will need to place the zip file (purity) onto the sd card. then you will go back to the phone and unmount. once your done with that its time to wipe the phone clean. do a system wipe, cache wipe, and data wipe (dont wipe the sd card) go back and then say install zip. choose from sd and pick that file. It will do the rest.
Good luck