Cannot uninstall SP1 in Win 7 64 bit

I need to do a repair install,because of issues with my Add\remove windows features screen stays blank(and I have Tried everything to be able to resolve it),but when I try to uninstall SP1 I get the error "error,some of the updates could not be uninstalled. I also tried this with the command prompt also to no avail.
Reading Shawn's tutorial on a repair install, I must uninstall SP1 to do a repair install right? Because my Win 7 installation disk does not have SP1. I really only want to do a repair install,because I would like to keep everything as is.
Bottom line: Must SP1 be uninstalled to do a repair install? Must I do a clean install? I'm confused about this

I did not run the Sp1 Disk cleanup tool. I have 920 mbs of service pack files in disk cleanup.(I did not delete them).
Sp1 will not uninstall,like I said,I get the error message"(some updates could not be uninstalled sucessfully." So I can do a repair install ,even though I cannot uninstall SP1.?

I used to use a reg hack to "fool" both the system and a couple of programs into thinking that SP3 hadn't been installed onto Windows XP. I was just wondering if something similar could be used so you could fool the Windows 7 system into thinking SP1 hadn't been installed. You could then (maybe??) do a repair install?
These were the reg files used:-
SP3 to SP2:-

Code:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]
"CSDVersion"="Service Pack 2"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Windows]
"CSDVersion"=dword:00000200

Back to SP3:-

Code:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]
"CSDVersion"="Service Pack 3"

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Windows]
"CSDVersion"=dword:00000300

A quick peep reveals there's something similar under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion in Windows 7.
I'll throw it open to the experts!

Whether or not you get this resolved it's time to think about using a disk imaging program to take a snapshot (image) of your system before you do any major changes to the system. Like a SP install. And to use it on a regular basis so when and if you run into problems you can get back to a clean system without having to go through a RE-Install.

These imaging programs have been my savior many many times. Well worth the cost.

There are also free imaging program that as far as everyone on this site says work very well.