AVG Antivirus removal problems

After a trial period I have uninstalled AVG free anti-virus and tried to install Kaspersky. This new anti-virus could not be installed since AVG has left many residual entries in the registry. I tried to clear these enteries which made my system unstable, so I restored to my last stable restore point. Could you please advise on how or which entries can I delete to be able to install new anti-virus without causing problems to my system.
Hello Amjad Khan, welcome to NST.
Get RegCure, run a scan with it, and then click on the Repair button to fix all the problems it found.
Then try installing Kaspersky again.
Revo Uninstaller is freeware which you can use instead of the app uninstaller. It will call the app version, then do a deep registry scan to remove traces.
I used it when AVG 7 to 8 upgrade failed on one of my systems leaving me with an AVG that wouldn't install/repair/uninstall.
Revo cleaned it all up and the AVG 8 then installed from scratch with no problems.
If you've already uninstalled AVG, it probably won't be any use to you this time, and a straight registry cleaner like Jake's link or Eusing or CCleaner will probably be needed.
It might be an idea to get a copy for future use though. I use it whenever I want to uninstall anything. It invariably finds masses of cr*p left behind that the app uninst didn't bother with.
Thank you for your suggestions. I installed and uninstalled AVG using Revo. I deleted all entries relating to AVG on advance facility. On boot up my system complained on the loss of some drivers etc. So I retored to stablise my system. I have also used Ccleaner and is one of the best utilies I use regularly. However, I am not entirely sure registry cleaner in Ccleaner will not have the same effect. I am now relucant to keep doing this, the more I try doing different things the more problems I create. Please advise which specific entries I should remove from my registry without any detrament to my system.
Revo gives you the list of all the registry entries and files/folders it's found which it asks you to confirm.
You can see that all the stuff it deletes is related to the app you're uninstalling. If your system has lost some drivers ! that sounds like you've got other problems.
AVG installs a few drivers with its product, though the uninstallation should have removed them without you getting errors from the system. Revo does occasionaly catch and delete stuff by accident that other applications depend on besides the application you're uninstalling, but thats why it displays everything its going to delete and gives you the option of whether or not to delete it.

Let's try this again with Revo. When you select AVG from the list and hit uninstall, choose the "Advanced" option (below the normal option that's pre-selected) which well launch the application's uninstaller first and than scan for leftover registry entries/files a lot more thoroughly than the normal uninstallation would.
AVG Romoval

I bought Regcure as recommended by somebody and this does not work. Although it shows as if it is cleaning the system, it does not, at least not to an extent that could be called deep cleaning. I reinstalled AVG 8 again and ran Revo to uninstall it as before. However, this time I used a few utilities to clean my system first before uninstalling. It has worked, I believe that I have finally got rid of AVG.