Laptop repair: how to get new OS and keep programs?

Clean install means a new OS and that also requires reinstalling the applications. There's absolutely no way you can do a clean install of the OS without wiping out the applications.

As for your files, you may still be able to keep them in your hard drive unless you format it. Nevertheless, it is still strongly suggested that you back them up on a separate storage.

Want to upgrade the OS without Formatting and keep all the files and programs then the best option is to upgrade the Os with the Same Edition .. Means if you r using Professional then use win 7 Professional and if using other then upgrade with the other of same edition

You wouldn't be able to. XP to 7 upgrade REQUIRES a clean install. You can use Windows Easy Transfer to make it easier, but you must still back up your data some way and reinstall your applications.

You can't. Windows XP can't be directly upgraded to Windows 7. It's easy enough to back up and transfer those files you need to save but all programs will need to be re-installed. Sorry.

It cannot be done, unless you go XP --> Vista --> 7.

"Clean install" means you have to wipe the drive.