Service Packs and Product Keys

I Know this is forums is for Windows 7 but, I have a question across the board with Windows.

I have a Windows XP Home Machine with originally product key sticker (no Service Pack). I've lost the disc. But I have a Win XP Home SP3 service pack CD. If I do a clean install of Win XP Home SP3 would the original product key be invalid?


Thanks

Currenty I have no Job, so I've offered to volunteer in my local school.

They have a number of machine ranging from Win XP Home to Pro and Vista and Win 7.

They don't have the CD and wanted to get one CD for each version of windows OEM and retail to cover all the product key i.e. sp1, sp2 etc...

Thanks, in which case if I was Used a Win XP Home normal cd (no service pack) Would a product key of a Win XP Home sp1, sp2 and sp3 work with the CD?

I've run into at least one situation where I tried to install XP Home (OEM) with SP3 and it wouldn't accept the product code on the sticker. Started over again with a non SP CD and was able to install using the code on the sticker.

I sometimes use XP SP3 installer to Repair or reinstall XP which came with no service pack or a lesser Service Pack. It is certainly worth trying but be sure to use the correct version and OEM if it came preinstalled on the machine or was builder's OEM XP.

For me to be covered in all areas of Windows XP.

Should I get a copy of Win XP Home SP3 - this would cover me for non SP, SP1, SP2 and SP3 and should I do the same for XP Pro?

I use the non SP XP cd's when working on PC's for friends and family. Haven't had a problem entering a product code with that disk yet. Mind you, thats probably less than a dozen PC's total. As mentioned above, I've had to start over once or twice after trying a SP3 CD first. On my own PC(s) I use my XP + SP3 CD because I know my product code will be accepted. Its been my experience that it usually doesn't matter if it is SP or non SP install media, but XP seems to be picky at times. It may have something to do with one of the service packs adding more than just updates. I've gone though 95, 98, 2K, etc, and XP is the only one I can remember ever giving me problems when entering a product code.