There are five root keys.
The question makes no sense. The registry is where the keys are stored.
you can find and edit registry keys by pushing Windows Key+R, typing regedit and hitting enter. registry keys are the settings for your operating system and all your programs. i would recommend not screwing around with them, it could really mess up your system.
Registry Contents • The Registry is hierarchical in structure - Made up of keys, subkeys, and entries • Registry key - A category or division of information within the Registry • Registry subkeys - A single key may contain one or more lower-level keys • Registry entry - A data parameter associated with a software or hardware characteristic under a key (or subkey)
On a local PC you can have an access to registry settings through registry editor. It allows you to have a low-level access to system settings and export them to .reg file. Using registry editor you even can access to registry on a remote computer. But registry editor wasn't designed to work with multiple remote PCs simultaneously. If you need to export registry keys from multiple PCs, you can benefit from the features of EMCO Remote Registry Exporter. EMCO Remote Registry Exporter is a tool that was designed to work in the network environment to export registry keys from one or multiple remote PCs. It can be used it if you need to check registry data on remote PCs or backup specified registry keys. Registry keys and values are extracted by the application from remote PCs and are stored in .reg files, created for every PC, so you can use them to find required information or use later on to restore registry settings. To initiate remote registry export operation you only have to define a list of keys to export and a list of PCs where export should be performed
Use hivesys.inf file for presetting Registry keys
To prevent your registry from becoming corrupt and some of them even scan your registry for bad keys wish can improve computer performance after getting rid of them.
System restore can be useful
yes
Generally they have the same structure , basic keys and values but there are many differences in other keys and values Some new keys appear in Win7 for example : if you want to change OEM information and add some description and Oem_logo to your computer properties , this can be done through registry in win7 , while in Xp you just put the text and the logo in your system32 folder Also in Win7 we have some new features like transparency , Aero ... etc all these stuff have key entries in registry So you can say , Win7 registry is bit different you need to search the internet to discover what is new in Win7 registry.
keys
Hkey_classes_root