Those backups do not get uninstalled after a set period of time though and can quickly accumulate to a size of 200+ Megabytes. The files can be simply deleted in the Windows folder. Users who prefer to use a software can use a tool called Remove Hotfix Backup Files which removes the files automatically.

It should be save to delete those backup directories if you have worked with Windows for several days after installing the latest patch from Microsoft without encountering a problem. Only patches that affect Windows XP will be removed by the software, patches installed for other software like Windows Media Player or Internet Explorer will remain.

Users who want to be on the safe side make a backup of the folders by either burning them to a CD or DVD or moving them to another folder or drive. If something goes wrong the folders can simply be moved back to the Windows directory.

The only negative effect of deleting those folders in your Windows directory has is that you will not be able to uninstall those Microsoft updates anymore. While most users could without doubt delete those $NtUninstall folders some might want to have a backup plan.

Instead of just deleting the folders you could first back them up on CD or DVD. This would ensure that you could copy them from the backup to the right location again if you wanted to uninstall a patch or service pack.

A quick check revealed that all those folder used roughly 200 Megabytes on my hard drive in compressed state. I personally feel that this is a bit to much and decided to delete those folders. I really can’t think of a situation why I wanted to uninstall a Microsoft update that I installed a while ago.

I would probably wait a few days before I would delete a folder from a brand new update which could make problems on my system but the older ones ?