You may be correct. I think that Microsoft is going to require a fully patched and updated version of Windows 7 in order to perform the upgrade, although at this point they are suggesting that SP1 will be sufficient.
I still suspect that certain KBs will be additionally required to go forward.
The first thing I might suggest is contacting Dell. They may be able to supply you with the necessary recovery media. If your computer is still under warranty it is generally free. If not, there may be a nominal fee.
Additionally you computer may have a recovery partition from which you may be able to reset your machine to the condition it was in when you first purchased it.
You'll want to perform a system image / backup (both) to secure your critical data before attempting either.
Lastly you should be able to secure installation media directly from Microsoft here
http://www.microsoft.com/en-us/software-recovery
But that will require a product key.
You may want to remove your email addresses from your signature as well as elsewhere in your forum profile. Having them available to public viewing may result in an incredible amount of spam email.
There are webcrawlers out there dedicated to acquiring such things just for that purpose.
