Virus attack and infection

I’ve been working with Win 2000. Today I received e-mail which is included virus. And I had already installed an antivirus program (norton antivirus) Althougt it found virus, virus infected my computer. Within a minute I couldn’t run any .exe(alsoregedit.exe) file which is already installed on my computer. I realize that “HKEY_CURRENT_CONFIG” and “HKEY_CURRENT_USER deleted in the registry. I display registy on network. Now some of system files are working and someof them are not working.
Is there any solution to rescue all installed programs(not only data)?Or sould install win 2000 again?