Test your memory for 5-6 passes with memtest86 bootable CD, then the HD using maker's full diag/repair CD scan:
http://www.tacktech.com/display.cfm?ttid=287
Have you tried IE8 in Win7? They finally perfected it with better features IMO than any other browsers, and it is rock solid stable with no issues in 100+ installs here. Perhaps you could hold off on another browser in your reinstall until you give IE a good run. Look at all the ways you can sort your History to get back to places you want.
Wiping your HD is an important first step as it will overwrite any infected or conflicting code. Use tutorial linked:
http://www.sevenforums.com/tutorials/91339-ssd-hdd-optimize-windows-reinstallation.html
The installer is mostly driver-complete with newer arriving quickly via optional Windows Updates. Any drivers then missing in Device Manager can be found on the Support Downloads webpage for your computer or device model. I would not change any drivers given by installer/updates unless performance dictates, then start with display, chipset.
I install programs slowly over time to gauge performance after each. I don't let any programs write themselves into msconfig>Startup except AV (lightweight free MS Security Essentials or Avast 5) and gadgets - any others freeload on CPU/RAM and can spy on you.
When it is finished, clean and order your HD perfectly with state-of-the-art CCleaner and Auslogics Disk and Registry defraggers monthly.
If performance probs persist, google text and ID# of repeat errors in Event Viewer>Admin View to learn how others solved them. Click through WEI score at Computer>Properties to resolve any cued issues on Advanced Tools page, work through errors in the Performance log found there, and Generate A System Health Report. Monitor processes working at idle closely.