We don't know from your post which version of Windows you have or whether you successfully previously installed SP1.
I also do not remember whether there was an expiration date on the offer or not, but I clearly remember at at least one point in the past for Windows XP that Microsoft offered free phone support to anyone who was having any problems getting one of the service packs installed.
Google for
Microsoft support install SP2
finds a substantial number of hits from Microsoft. I would hope you might be able to trust those more than you can trust some raving nut who is for or against SP2.
Since you have already reformatted your drive there are perhaps fewer options. One that you might consider is to create a "slipstream" CD. This is a CD with all your original Windows files that were unchanged by the SP and all the updated files from the SP integrated into a single install CD. I would also make certain that you have a CD containing any and all drivers for your hardware that were not so standard that Microsoft already included those on the Windows CD. I have had installs where a handful of the Dell drivers were not included and the machine was not functional enough to be able to get the needed drivers by itself half way through installation. I would recommend that you have another working computer sitting right beside the one you have so you can use the working machine to do Google searches to answer questions and fetch needed drivers during the install process.
At least for Windows XP, SP1 seemed to be a much bigger problem for many people than SP2 was. I heard very few people who killed a machine going from SP1 to SP2 and that was not the case going from XP to SP1.
So, read all the official directions from Microsoft, follow all those and perhaps do some of what I suggested above.