Reinstalling - will I lose my themes?

[microscopes]

1) I have 4.2 ... I want to reinstall it because plugins and mods have made it so slow. What's the best way to do a fresh install of the same version you have right now?

2) will I lose my themes? Any way to save them?

[Zachery]

Just uninstall your addons. reinstalling won't really fix your issues, plus you'll lose all of your current data.

[AusPhotography]

Good addons are excellent and help sites, but only use them when they add real value.

Some actually improve performance :)
Eg. https://vborg.vbsupport.ru/showthread.php?t=284816

Also there is much you can do to tune vB's performance, just do some searching on this site