registry cleaners?

why do people always say that you should only use a MICROSOFT branded registry cleaner instead of any otther registry cleaner? and if its true then could you tell me a website for a FREE microsoft registry cleaner? if not, could you tell me a website with a FREE registry cleaner? ty

FROM A WEBSITE ON SFC:

To protect your computer from old system files, Microsoft created a special service that is built into the operating system. This service monitors your system files, and if one is replaced or deleted, ICS will automatically restore the system file.

SFC works in conjunction with a utility called Windows File Protection that keeps the system file cache: (%Systemroot%\System32\Dllcache) uppdated with the newest Microsoft Approved files as they are installed on your system. I prefer to use the system backup for the ability to roll back to a former configuration however.

To manually invoke the system file checker, be sure you have administrative access then go to the command prompt and type:

sfc /scannow

The system will immediately begin to check all the current system files and restore the cached approved copies. You may be asked to insert the Windows CD as well during the restore.

IS THERE ANY SOFTWARE AVAILABLE TO DOWNLOAD SO THAT I DONT’T HAVE TO USE THE CD?

I have a virus on my computer that is mainly located in this Loaction…HKCU\Software\Microsoft\Windows\CurrentVersion\InternetSettings\ZoneMap\EscDomains. I have no idea what HKCU is and where to look for it to manually remove the files attached to this trojan. I do not have the money to pay for software or even worse a PC repair shop so I’d like to manually delete.

This happens all the time!!! it drives me crazy, i got a corrupted hal.dll at first and just fixed that, not it restart when windows just finish loading. Repair windows option is not available, is there a way to force it? I tried running windows xp in safe mode and install xp, but it keeps telling my key is not correct. So i tried Vista, but i didnt have a key, so i just choose the no key option which i need to activate in 30days or it wont work anymore. But it says cannot upgrade in safe mode! Is there any way to bypass this, i read around alot n there was ways to swap mobo through microsoft software, but mine is dead. I have no clue!!! Please HELP. THX!!
I know y it doesn’t work, but does anyone know how to fix it? Where is the drivers and stuff located thats causing this? Is it possible to install the same XP on a different hdd on teh same comp, then just swaping the drivers/files to the old hdd? but then were is the file.
Its from a amd processor to a amd processor amd to my p4 intel works. o.O
I dont like vista also, but even that dont work so idk. There are alot of games and programs there too so thats something that i dont think slave would work in. but thx
My old 200 GB is a slave and my 40GB is on master, BUT i can run my preinstalled GAMES or PROGS… which is most of my disk space.

My computer started showing some problems like "could not read memory from"—– something it shows blue caption with white words saying win xp has stopped working due to some problem. Sometimes it does not boot properly close and starts many times. I tried to repair it with windows cd but few files were not copied saying these are corrupt. I formatted it and and installed fresh xp then I went to Microsoft site to updated. After downloading few files it restarted and again behaving as it was doing before I installed new Xp. My earlier xp installation worked for 9 months. Please help what to do. How to solve this. Is there free software that can repair Xp? What are the indications if RAM is not working properly