some control panel applets are lost - win 7 pro x64 -

[STephan]

Somehow some applett (e.g. Windows Update) are lost - get error-msg application missing.
Is there a list of these applets and from where can I download the missing ones and which is to be stored in which folder?
For some days ago I was plagued by a pop-up panel in firefox: Repair Windows 7.
I closed it each time, assuming, that it was malware . It could be, that this was the culprit, that removed some applets. Previously they were there, I was using them.

 

[TrainableMan]

I suggest you first run a complete virus scan on your computer. You might even want to burn Windows Defender Offline to CD/DVD and then boot your computer from that CD/DVD you made and have it scan for viruses without Windows running.

Then I suggest you open a command prompt with Administrator privileges (right-click on command prompt and choose run as an administrator) and type:
SFC /scannow

You could also boot to the W7 Installation DVD and go to the Install Menu. Instead of Installing choose System Repair (at the bottom left) instead.

If you know when the problems started you could type System Restore in to the Start > search box and run System Restore. When it lists the restore points, check the box at the bottom to show more restore points and if there is one before the issue began then you could restore the computer to that point prior. Note that anything you installed in that time (such as Vistalizator) would be uninstalled. Before you confirm the restore it will tell you what programs will be effected. Any you want after the restore will then need to be reinstalled.