Do all these software updates take up more and more disk space?

If I Could Turn Back Time...

If you can roll back an update, it's almost certain that the files that update replaced are still on your machine. That means that the update process is slowly taking up more and more disk space.

Windows is a great example.

An older article, Can NtUninstall folders be deleted? actually shows that a certain set of folders are created when updates are applied, for the express purpose of being able to revert from those updates. In fact, if in Windows XP you go to Control Panel, Add/Remove programs and click the "Show updated" checkbox:

you'll find that you have a much longer list of items as all the individual updates are enumerated. Many of them include the ability to be removed, implying that the files that they replaced have been kept on your system for just such an occasion.

An Update is an Update is...

Not all updates are created equal.

For example, your anti-malware tools should be updating their databases daily. Would you ever consider or want to roll back to the previous days database of malware? That seems unlikely. So unlikely that the update process is a true replacement - today's malware database replaces yesterdays. Aside from the difference in size between the two versions of the database (it's pretty likely that today's is somewhat larger than yesterdays, simply because new viruses have been found and added), there's really no cumulative growth in size.

Software manufacturers can choose to have their updates operate the same way. An update to Flash, for example, is pretty likely to replace the previous version completely. In fact, I'll go so far as to say that most software updates work this way, and that it's Windows and some Microsoft products that are the exceptions by providing the ability to roll back an update at all.

But this is a choice made by the designers of the software. Most will choose to replace previous versions completely, thus not adding dramatically to the disk space used. Others may offer the ability to roll back individual updates, which of necessity typically means that the old files are preserved somewhere.

Should You Care?

In a word ... no.

Honestly, if you're running low on disk space then there are probably easier ways to get more disk space the chasing after accumulated updates. Get a disk space display tool (there are several) and see what's taking up so much space. There's a good chance you'll find that it's not updates at all, but more likely things like caches, temporary files and a host of other random things that are easily identified as being large, and quickly dealt with to recover space.

And if you're not running low on disk space, then there's not really any point to trying to figure our the cumulative updates thing. Leave that for another day, if ever.