Reformatting your computer should always be a last resort.
If you're unsure how to use MSCONFIG or what to remove, download Windows Startup Inspector and scan with it. Then click Consult and it will tell you what to leave and what to remove. You can do it within the program safely.
If it's still to slow after that, post back and we'll make some other suggestions.
-------------------- OK OK I can't go any faster! aaaaaaaaaaaagh!