Vista - Unable to Install Win Vista SP2

I have Windows HP with Vista Sp1 installed on my Black Viper tweaked pc and am very satisfied with its performance ; however I wish to install Win Vista SP2 and have run into major roadblocks . I have read through many suggestions on this topic but still no joy after a month or more of trying . Initially , the download would start , then stop after 99% was installed and revert back . Now when trying to install , I get a message that SP1 is not installed and I must install it first . SP1 is installed but I tried to reinstall it to no avail . When trying to reinstall SP1 I get a message that SP1 is already installed , then the reinstallation stops . !! Yet , my attempts to install SP2 tell me I must first install SP1 . I have tried the SFC / SCANNOW and chkdsk /r repairs to no avail . I have also tried repairing my system with the Microsoft OEM HP installation disk but the repair does not address my issues . I do not wish to reinstall Vista from scratch since my system is working very nicely except for this glitch . I am chasing my tail and need some help with this problem . Thank you .

I think this is similar problem :SP2 is saying to install SP1 first, but SP1 is installed

Help and Support

tech support for sp2 is free (for a while).

Thank you Flavius & kword88 ; I tried your sugestions most of the day and still no success . I backed off when vLite wanted to reinstall since I did not want to lose my current programs and configuration . I wrote to Microsoft and await their reply . Thanks again for your advice . I'll keep you posted.

i would call. (but, thats just me i guess)

This morning I received a very detailed response from Microsoft which totally mind boggled me with their superb , pleasant support . The apparent cure for my problem is tedious and I responded by asking if installing Windows 7 , which I have prepurchased will cure my difficulties . I'll keep you posted .

Thanks for the update.

It would be great if you could post the solution MS emailed you.
Very useful for others with a similar problem.

Thanks