All you tell: "i tries to re-install office 2007..a number of time but it showed an error".
That's not much. Not even information about the error. All I can say: clean up the old install as described in http://support.microsoft.com/kb/928218/
If that isn't enough, try the Windows installer cleanup utility from http://support.microsoft.com/kb/290301, but note that Microsoft doesn't recommend to use it for Office 2007.
previously i had installed microsoft windows xp sp3 twice on my system on different hard disks then by mistake deleted the office in one os..it got dleted in the other os too....i tries to re-install office 2007..a number of time but it showed an error...hence i am unable to install....at present i have only one windows xp sp3 on my system
my processor capacity is 2.66Ghz and 1GB ram...i even directly downloaded microsoft office from microsoft website...still it would'nt install...even the office related updates are not installing....every time i try to install them half hour later it says the following updates were not installed andshows ...the following
2007 SUITE MICROSOFT OFFICE SERVICE PACK 1
SECURITY UPDATE FOR 2007 MICROSOFT OFFICE SYSTEM(KB960003)
AND FEW OTHER SECURITY UPDATES FOR OFFIE RELATED PRODUCTS AND 3 UPDATE FRO OFFICE RELATED PRODUCTS...PLEASE HELP ME...I URGENTLY NEED MICROSOFT WORD..TO WORK ON..I HAVE TRIED STAR OFFICE WRITER BUT I AM FACING DIFFICULTY BECAUSE TO print a document i have to transfer it to another system and that system does not have any thing else but microsoft office 2007/2003 hence either the formatting changes or at times the FILE DOES NOT OPEN AT ALL....SO PLEASE TELL ME HOW TO INSTALL OFFICE 2007