How do i revert everything on Windows 2000 to its "right-after-install" state?

Hello
My windows2000 advanced server started rebooting itself after 15 minutes of
starting up the system.I tried to install the latest service pack ( it was
srv pack) 3 then,but while install,it rebooted! So the system files got
corrupted.. I downloaded the whole service pack 4 (when it came out a few
days after this incident) and installed it locally. Now it doesnt boot after
15 min but it gives windows file protection errors and it cant connect the
net. it CAN ping but it cant connect on ftp or http. it CAN connect when i
am on win98. so it is not a DNS problem on win2k.
I uninstalled srv pack 4 and now it can connect but reboots after 15 min
like it did before. it still gives windows file protection errors.
I thought and decided if i can revert everything including the system
files to "right-after-install" state, then everything would work normally.
Is there such tool microsoft released or is there an official way or
unofficial way to do it? Dont tell me to have a ghost image after install. I
didnt have because it wasnt compatible enough for me.And now i dont have
such image so lets talk about what we can do;and that is:
How do i revert everything on Windows 2000 Advanced Server to its
right-after-install state?
Thank you.
Email: overclock_addict@yahoo.com