|When you run sfc /scannow, the source must have the same Windows SP1, SP2, or SP3 , or no SP updates, integrated into it as the present Windows installation on the hard drive, otherwise SFC will not accept it as a valid source of files.|
E.g.. if your Windows CD does not have SP3 updates integrated into it, SFC will not accept it as a valid source if Windows has had SP3 updates integrated into it
The source probably must be for the same version of Windows as on the Windows installation - Home, or Pro, or Pro 64 bit.
You can make a "slipstreamed" burned Home or Pro or Pro 64 bit CD, preferably a CD-R for best drive compatibilty, that has the SP3 updates integrated into the contents of your original Windows CD,and that will be accepted as a valid source by SFC. Sometimes you will need to click on Retry many times when SFC claims it can't find a file on the CD, especially if the burned CD was not made in the same drive it is being read in, but it will complete eventually.
You can't integrate the SP3 updates into the contents of the OEM XP MCE 2 CD sets, so you can't successfully use SFC /scannow for any XP MCE version if SP3 updates have been installed in Windows.
(You CAN run SFC /scannow successfuly if you un-install the SP3 updates in Add or Remove Programs BEFORE you run it, for MCE 2005, which has SP2 updates built in.)
"actually I happen to have a slipstream of my xp home with SP3, but only SP3, no updates that have come since."
It's not necessary to have Windows updates that came out after SP3 updates integrated into the source, as far as SFC is concerned.
"I had a failed attempt to use it for a repair/install due to product key from my original(and legit) xp home disk not working"
The original Product Key WILL work with Setup with the slipstreamed CD with SP3 updates integrated into it
- if the slipstreamed CD was made using the contents of the original CD, for the same version of Windows as the Windows installation on the hard drive, Home, Pro, or Pro 64 bit
- OR - for a brand name computer, if the slipstreamed was made using the contents of an original Microsoft OEM CD, for the same version of Windows as the Windows installation on the hard drive, Home, Pro, or Pro 64 bit.
A Microsoft OEM XP CD has "For distribution with a new PC only." printed on it and has the Microsoft holograms.
They will work for installing Windows from scratch with the OEM brand name system Product Key that's on the Microsoft label on the outside of the brand name computer case.
They will work for running a Repair installation of Windows too with the original Product Key, in most but NOT all cases.
If you use an original XP Reinstallation CD that came with another brand name computer model, or a slipstreamed CD made using the contents of one, it cannot be used to install Windiows fromscratch or to run a Repair installation of Windows unless the model you are using it with is the same.
You can't run a Repair installation of Windows unless the Windows CD is the same version as the on the hard drive - Home, Pro, or Pro 64 bit - the second Repair choice in Setup will not appear if they are different.
I found out recently that the Product Key you use for Setup when you do a Repair installation must be one that is accepted by the Windows installation already on the hard drive, not necessarily one that works when you install Windows from scratch - I had a legitimate key for for a volume licensed version of Pro that works fine when you install Windows from scratch, but I had to use a Product Key for a retail version of Pro for Setup to accept it when I used the CD to run a Repair installation of someone else's Pro installation.