Scheduled Tasks Mess Up

I have deleted some unwanted scheduled tasks (The programs that can't be installed due to compatibility issues) through C-Cleaner.

But, I ran into severe problem after that.

My appearance of Windows 7 goes rough with some lines (like Classic View).

Please take time to read these threads,

http://answers.microsoft.com/en-us/windows/forum/windows_7-performance/c-cleaner-and-systemregistry/17cf1efd-54f0-4be9-bece-ba136a2f6ff0

http://answers.microsoft.com/en-us/windows/forum/windows_7-desktop/changing-classic-appearance-of-windows-7/497f4a96-671b-46cf-9fd3-44547733f143

Then, I scan my Registry with C-Cleaner recently.

It shows 31 issues.

But, this time, the issue seems to be on system files!

I fear to fix whether they may lead to system unstability!

Please see the threads help me with the issue!

have you tried going back to previous Restore Points?