By default, Windows keeps the Windows.old folder around for 10 days after such an install. If you’re sure things are working, you can remove it sooner. On the test Windows 11 PC whose Windows.old folder weighed in at just under 35GB in Figure 1, running Disk Cleanup (cleanmgr.exe) returned nearly 25GB worth of disk space, as you can see in Figure 4. That process took about 5 minutes to complete.
Figure 4: Disk Cleanup offers to recover 24.4GB on the repaired Windows 11 PC.
Ed Tittel / IDG
A strategy for using Windows in-place upgrade installs
Knowing that I can perform an in-place upgrade install quickly and easily has really changed my outlook on Windows troubleshooting. Except for hardware problems (or driver issues, which tie directly into hardware as well), if I find myself spending half an hour troubleshooting a Windows problem, I’m already asking, “Is it time for an in-place upgrade install?” Once that time spent stretches past one hour, there has to be a compelling reason why it’s not a good idea to perform an in-place upgrade install to keep me laboring away at other things.
Simply put, an in-place upgrade install is a great solution for resolving trying or opaque issues with Windows — as long as the target OS is still running well and long enough to run setup.exe through the first of the three or four reboots typical during Windows 10 or 11 installation. If you can make it to the first reboot, the new OS takes over after that anyway, and most problems will be fixed.
