Husain,

Have you uninstalled, ran something like CCleaner to clear remaining entries and then reinstalled Maya on the original computer?

Uninstall Autodest Maya 2010 and delete its folder in Program Files.

Also download CCleaner from CCleaner - Download
Then install.
I suggest when asked untick all the options apart from the top one

CCleaner:

Under the Cleaner section: select “Run Cleaner”

Under the Registry section: select “Scan for Issues”

(when asked about registry “Backup” save & then accept where it saves it to.)
then “Fix Selected Issues”

Do the Registry option again..(and again until no issues found)

Reinstall

elpmek, thank you very much!I've done all what you've told, but it is still not working Regards,HUSAIN

So given the above you've reinstalled Autodesk Maya 2010 and still it doesn't work.

As I can't think of an application myself that uses Alt + Left Mouse I suggest you contact the Autodest Maya people.

Others in the forum may have better ideas............