edit on title:
Will files get corrupted/ become unusable on other computers?

if it happens that i deleted registry keys accidentally and some programs are not functioning properly, will it...

1) affect the files that i download and cause them to be unusable even in another computer?
2) affect the files that i burn and cause them to be unusable even in another computer?

coz i need to know if stuff that i download or burn will get affected or not.
thnx alot.

You better don't touch to registry keys.Do not delete them and don't use registry cleaner programs.Your burned cds or other programs are not affected but your windows won't work fine.You'll see many error messages ,etc.I myself cleaned registry once then could not repair my windows and at last formatted my pc and reinstalled windows.

How in _ did you...

Well forget that. But I have never seen a discussion of the registry, that even mentioned the possibility of editing it, that did not very emphatically insist on the need to back it up before editing it.

As far as damage to your machine's ability to function, registry "accidents" are often fatal. You can count yourself lucky it boots successfully.

The effect on future operations depends on what you deleted. My suggestion is that you restore the registry from backup, if you have a backup. HOW you do that depends on what OS you are running.

A Google search on [ registry restore windows (your version) ] will get you a listing of web pages you can use to learn about this. I'd start with the Microsoft pages.

If you cannot restore because you have no backups you can always try running with the registry in its current state. When software does not run due to registry errors, try removing and reinstalling that software. If you cannot remove the software using system tools like "add and remove software", then do internet research to determine how to do manual uninstalls. (Do not think that removing the files and folders for the program will solve any problems, unless it is a virus or similar problem software.)

You can also investigate registry cleaning and healing software. I've never used it, and cannot recommend any package or approach to this though.

Good luck.

Here are what should be good references to registry information from SANS

"How to protect against Anonymous Logon problems on your systems. IMPORTANT Note: This article contains information about modifying the registry. Before modifying the registry, make sure to back it up and make sure that it is understood how to restore the registry if a problem occurs. It is recommended to thoroughly test any modifications before implementation in a production environment. For information about how to back up, restore, and edit the registry, click the following article numbers to view the article in the Microsoft Knowledge Base:

256986 - Description of the Microsoft Windows Registry
323170 - HOW TO Backup, Edit, and Restore the Registry in Windows NT 4.0
322755 - HOW TO Backup, Edit, and Restore the Registry in Windows 2000
322756 - HOW TO Backup, Edit, and Restore the Registry in Windows XP Windows Server 2003 "

The links are at http://www.sans.org/top20/

I'm trying to find if there is such a thing as a reliable, useable, registry cleaner. The one you used caused problems for you. What was it's name? Who made it?

I wouldn't say that there are too many "reliable" registry cleaners out there, in fact most are overzealous to say the least. So if you do use one, always be sure to verify the entries it wants to remove first, and even then I'd only stick to the entries which *directly* pertain to any programs or applications that you know you have uninstalled.

I've mentioned this one before here, and it is probably one of the better all round cleaning programs out here. JV16 PowerTools (the last freeware version) is a good one to use.

It can be found at OldVersion.com

The best one I know is CrapCleaner:

http://www.ccleaner.com/

it has never ever caused any registry problems, and I use ERUNT to backup the registry before editing:

http://www.larshederer.homepage.t-online.de/erunt/

I also use JV16 PowerTools, and it works pretty well too as long as you only delete "green" entries.

Thanks to you for the information. I will be checking out CCleaner, JV16, both, and checing to see what ERUNT is too.