Btw,im confused which one to pick,ERE27 are optional,the other one is with himem enabled.how to check wheter mine is enabled or not ?
Ok for all the noob want to roots your nexus, here the guide i use that you can get at www.unlockr.com
I.
Root the Nexus One1. Download Superboot (first download link on the page)
Superboot
2. Once it is saved to your computer, unzip it to your C: by right clicking it and clicking Extract Files…
Once it is extracted to the C:, rename the folder to Superboot (this will make life easier later).
3. Turn off your Nexus One and then plug it in to your computer via USB cable.
4. Turn the phone back on by holding down the trackball and hitting power (keep holding it down until the fastboot screen comes up).
5. Open the Command Prompt on your computer by opening the Start Menu, then either typing cmd and hitting enter in the search box (for Vista and higher) or by clicking Run and typing cmd and hitting enter (for XP).
6. Once it opens type the following with hitting enter at the end of each line:
cd\
cd C:\Superboot
fastboot-windows devices
*Your phones serial number should display proving that it is connected and your computer can see it.
Then type:
fastboot-windows oem unlock
7. Then follow what the screen says to do on your phone and select Yes.
*You may get an error in the command prompt, just ignore it.
**Also your phone may reboot, if it does just turn it off, then turn it back on by holding down Power and the Trackball to get back to fastboot before continuing on to the next step.
8. Now, while the phone is still connected, go on your computer to the Superboot folder and open it. Inside you will see a file called, install-superboot-windows.bat
9. Double click install-superboot-windows.bat and wait for it to finish. All done, rooted!
II.
Flash a Custom Recovery Image1. Download the Nexus One Amon Ra Recovery Image below:
Nexus One Recovery Image (Link under Download in the first Post)
2. Save the recovery image file inside the superboot folder you used to root the phone.
3. Turn the phone off and then plug it in via USB cable.
4. Turn it on by holding down Power and the Trackball to get into fastboot mode.
5. Open a command prompt and type the following with hitting enter at the end of each line:
cd\
cd c:\superboot
fastboot-windows devices
*this is to check that the computer can see the phone (a serial should pop up if it can)
6. Then type:
fastboot-windows flash recovery recovery-RA-nexus-v1.5.3.img
7. This should flash the recovery image onto the phone.
III.
Flash the Custom ROM1. Download the ROM you want from our Android ROMs section. (Make sure to choose a ROM for the Nexus One and not another phone!)
2. Turn off the phone.
3. Turn it back on by holding down Volume Down and Power until the bootloader screen comes up. Let it finish searching then select Recovery by using the volume buttons and click power to select.
4. Once the recovery screen comes up, select Nandroid Backup (to save a backup just in case, optional)
5. Then select Mass Storage On and plug your phone into the computer.
6. Copy the ROM .zip file to your phone’s SD card then unplug the phone.
7. Click USB MS Toggle.
8. Click Apply .zip from SD Card and then select the ROM you just copied.
9. Wait for it to finish loading and click Reboot. All done!
wah,this is really useful for super-noob like me.hehe,thanks bro,im really imbecile in this gadgets stuffs.will follow your step one by one