i found this at xda, took 10 mins. super easy
Originally Posted by
Alexithymia 
Ok, Rooted ROM in 20 steps:
This is summarizing the steps from another xda thread (cant link as i am a new member) into a failsafe rooting procedure for me on VISTA:
1 Get the files on the link provided. Now copy over PC36IMG.zip to your sdcard on your EVO
2 Turn your Phone off
3 Hold VOL DOWN and continue holdint while turning the phone on. When the white screen comes on you can let go.
4 The phone will check the .zip file and run automatically. At two points it will ask for user input. Say yes both times by pressing VOL UP as directed on the screen.
5 Saying YES the second time will reboot your phone. Yay you're rooted. But you won't have superuser access with this rom. Therefore:
6 As soon as you are able after booting change the name of PC36IMG.zip to something else. Developers suggest "root-PC36IMG." Which is what I did (I renamed through mounting the disc drive via windows)
7 Now power your phone down and reboot holding volume down again. This time your phone will try to load something and fail (at least it did in my case)
8 It will provide you with options. Use the volume keys to navigate to "RECOVERY" and use the power button to accept
9 Your phone will display "HTC EVO 4G" then turn to a black screen with an exclaimation point in a triangle.
10 Connect your phone to your computer. In the evo-recovery files you downloaded, run recovery-windows.bat as administrator (by right clicking and choosing the option)
11 A command prompt will pop up and stream files to your phone. This in turn will enable options on your phone.
12 go to backup/restore using the same navigating you have been.
13 Choose nand backup and then confirm. This backs up your NAND in case you EFF things up. It will be stored in a folder on your SD card as NANDROID. be sure to keep a copy safe somewhere.
14 when its done return to the main system recovery menu and enable "USB-MS" which will mount your SD card. Copy over your Supersonic_1.32.651.1_rooted.zip courtesy of Flipz to the root of your SD and then untoggle "USB-MS"
15 Now navigate to "Wipe" in the recovery menu
16 navigate to 'Wipe data/factory reset" and confirm the selection
17 navigate to "Davlik-cashe" and wipe that as well
18 return to recovery main menu and choose "flash zip from sdcard"
19 Choose Supersonic_1.32.651.1_rooted.zip or the rooted rom of your choice and let it install. Choose to reboot your phone. (IF YOU SKIP STEPS 16 AND 17 YOU WILL BE STUCK IN AN INFINITE BOOT AFTER INSTALLING THE ROOTED ROM. This can be remedied by returning to recovery mode (after pulling your batery to stop the loop) and following steps 16 and 17)
20. Superuser access is now available.
Hope that helps