When you say
initiating, does that mean:
(a) the OS, (with crapware), has already been installed and it just finalises installation on first boot, or
(b) the OS has already been installed but it asks for discs to install the crapware on its initial boot, or
(c) that the HDD is blank and you want to prevent it being loaded from the recovery disc.
From what I've read online, (assuming Win7 here), there is no difference between install discs of HP, Pro or Ultimate, (barring the esoteric versions and obvious x86/x64 differences), whether OEM or not - the CD key is what determines which version will be installed and whether it's OEM or not. The main difference between OEM and retail is in the licensing agreement.
In theory you could download, (or borrow), a full install DVD of the version that's already on the laptop, (or a specific x86/x64 Win7 DVD of any version: HP, Pro or Ultimate and
modify it), install and then enter your OEM key - this should be done before the current version goes online and activates itself. The key will then be tied to the hardware, which in the case of an OEM license means specifically that motherboard - if it fries you need to buy a new OS also.
This will give you a bog standard Win7 install with no crapware other than what MS install by default.
EDIT: Forgot, you'll also need to download drivers for the specific hardware of your machine afterwards, (eg. thumbprint reader, etc), so you should check Dell's website to see if they are available for download first.