Can you use system restore in these situations?

I'm kind of a computer newby so I appologise if this is a stupid question for you techies out there.

Senerio 1

On day 1, I did a complete thorough antivirus and spyware scan check and removed all viruses, spyware, worms, etc on my computer. My computer is now "clean". I create a system restore point.

On day 2, after surfing on the net, for some odd reason, a large number of virus got installed into my computer. Instead of the using conventional remedy of running my antivirus program to remove to viruses, can I use system restore to go back to day 1 when my computer was originally "clean". Would that remove the virus that got installed on day 2?

Senerio 2.

On day 1 I ran a registery cleaning program to optimize my system. After doing so I created a system restore point. On day 2, I found for some odd reasons, my computer contained critical registry errors. Instead of running my registry cleaning program again, can I simply system restore to day 1. Would that fix the registry errors

Can you use system restore in these situations?photoshop

Usually the computer makes a restore point for itself.

but if u have made your own backup and it is not infected yes it will do the trick.

Can you use system restore in these situations?symatec

if that is some random generic registry cleaner it could have messed it up in the first place, and i dont think that restore would fix eighter. id do a virus scan , then a disk check. like the thing that comes up when you improperly shut your pc down.