I've installed Windows 7 on about 30 PCs at my work place and on a few of them I had to delete files before I can install Windows 7. On those PCs I've noticed that the Windows System folder for Windows XP was about 7GB in size Before I started the install of Windows 7. Now the Windows 7 is installed on the computers I have a "Windows.old" folder from the old Windows XP system. When I go into this folder I see the "Windows" folder and like I said earlier its still 7GB in size after the new install. I figured that there are files in there that are unnecessery but I didn't want to delete the wrong thing. Which files in this folder can I delete?

If you have to delete files before you can install Windows 7, then you're in serious need of larger hard drives especially if you're worried about 7gb. But if you have recovered the data you need from the windows.old folder then you can delete it.MCSE, MCSA, MCDST [If this post helps to resolve your issue, please click the "Mark as Answer" or "Helpful" button at the top of this message. By marking a post as Answered, or Helpful you help others find the answer faster.]

What you would need from the windows.old folder, is a question that can't be answered generally. But, think of an example: In your new Win7 installation, you might have lost the *.pst files from your old Outlook installation. You restart with an Outlook without history. If you copy the old *.pst files to the correspondent new directory, you've your old communications back. Think of more similar cases.Mobile AMD64 3000+, VIA Apollo K8T800 chipset, 1 G RAM, ATIRadeonMobility 9700, 20x DVDRW, C:XPSP3 (50G),D:WIN7 (30G),F:DATA (250G)

I've installed Windows 7 on about 30 PCs at my work place and on a few of them I had to delete files before I can install Windows 7. On those PCs I've noticed that the Windows System folder for Windows XP was about 7GB in size Before I started the install of Windows 7. Now the Windows 7 is installed on the computers I have a "Windows.old" folder from the old Windows XP system. When I go into this folder I see the "Windows" folder and like I said earlier its still 7GB in size after the new install. I figured that there are files in there that are unnecessery but I didn't want to delete the wrong thing. Which files in this folder can I delete? HiAs the others have already stated, the Windows.old folder contains all of the files from the previous installation. It has 2 uses.1. You can recover personal data and files from that folder.2. There is a procedure that allows you to use that folder to revert back to the prvious installation.If you have recovered all of your files and you are satisfied that you will not need to recover the old installation, you can remove that folder.To remove the folder, use the Disk Cleanup wizard. Go to Start, type disk cleanup in the Search box and press Enter.Select the 'Remove files from previous versions of Windows' option to remove that folder. Hope this helps. Thank You for using Windows 7 Ronnie Vernon MVP

OK, thanks for your replies. I was just thinking that those system files from Windows XP couldn't be deleted since I had to have a previous windows OS to do the custom install on the PC. As far as the .psst files and things like that, I already knew that stuff could be deleted. I was just talking about the critical files that makes the Windows OS work correctly.