Can't use system restore

Have tried several times to install Symantec Internet Security update for common client. Each time it's installed--email won't connect. Previously would just use system restore to go back a couple of days and get rid of update install and everything would work ok.

Tried common client update again yesterday--still wouldn't let me open email, but now when I try to use system restore, it keeps saying "unable to restore to date" please use another date--have tried several different days within past 3 weeks, but always get the same answer. Did some research, and tried it in safe mode, but that didn't work either. Any ideas how I can get system restore to work again ???

 

Ok see if this helps-- try getting System Restore in with the command prompt
Restart your computer, and then press F8 during the initial startup to start your computer in Safe Mode with a command prompt.
Log on to your computer with an administrator account or with an account that has administrator credentials.
Type the following command at a command prompt, and then press ENTER:
%systemroot%\system32\restore\rstrui.exe
Follow the instructions that appear on the screen to restore your computer to an earlier state.