|I take it that your quest is to get the computer working again (rather than fix the script). |
In which case the first step would be to see if you can get into Safe Mode by tapping F8 during boot. It so you can then delete the script and/or the AutoIt program.
If that doesn't work you could create a Live Linux CD. They run between the CD & RAM but you can access files on the HD. You can then either delete the script or the AutoIT from there. Windows should then start normally again if you remove the CD. I can help with the Linux Live CD detail if necessary.
In fact it might be neater (using one of the above methods) to simply rename your script file and the AutoIt exe file to text files (.txt) which will disable both of them.
Please do not post then vanish - let us know the outcome