How did Claude free up 143GB on his C: drive?

Computers need maintenance. A regular annual hardware and software maintenance routine is necessary for Windows laptops, but it's a time-consuming process. Unfortunately, the C: drive often fills up and needs freeing up space immediately.

Disappointingly (and perhaps not unexpectedly), Windows' Storage Sense feature doesn't know what's taking up space on your drive. So, instead of manually searching for old program files, documents, and leftover data from uninstalled programs, use Claude Code to do it, and it will find more free space than you expect.

Skip the cleaning apps! Ask Claude instead!

Why is Claude Code better suited for exploring a messy situation?

If you've used Claude on the web or desktop to diagnose system problems, you're already aware of its limitations. It can advise you on what to do, but it can't examine your computer. When you ask Claude to scan drive C:, you'll get an explanation of sandbox rules and a suggestion to use WinDirStat.

However, Claude Code is different. It runs directly in your terminal, executes commands on the actual computer, reads the output, and interprets what it finds. Give it the task of figuring out why your drive is full and what is safe to delete, and the results are surprising.

What it returns is a structured breakdown of every important folder, with a column indicating not only the size of each item but also whether it's safe to delete. The last part is what most Windows tools, including Microsoft's built-in ones, miss. They only tell you what's taking up space on your drive, but don't tell you if deleting them will cause any problems. This is also why many people abandon Windows Storage Sense in favor of a single command line.

Claude Code has discovered the resource-intensive tasks that Windows ignores.

Cache folders, duplicate files, and forgotten data lurk right before our eyes.

The biggest item Claude discovered was forgotten VirtualBox virtual machine images, taking up 72.6GB of space for virtual machines that hadn't started in months. 

Next are the AI ​​tools that were tested and, in most cases, installed. Except that the uninstallers forgot to remove all the downloaded AI models, and in some cases, the tool itself. LM Studio left 13.21GB of models, AnythingLLM left 7.1GB, Jan left 3.59GB, and GPT4All was technically still installed, and Nomic.ai had 1.79GB in AppData.

In total, these tools you thought you'd deleted take up about 30GB – none of them show up when searching for installed programs, all hidden deep within AppData folders that Windows' cleanup tools are completely unaware of.

Next up are Nvidia's cache files, totaling nearly 19GB across active locations. The largest portion consists of cached driver packages, accumulating after each update and somehow never being cleaned up. The DirectX shader cache adds another 5.19GB. Claude Code has marked all of this as safe to delete, clarifying that the shader cache automatically regenerates and driver packages are re-downloaded when needed.

The rest are smaller items you've forgotten about. A forgotten WSL Ubuntu installation of 3.4GB; easily removed with a single terminal command. Other deleted files include the npm nn cache at 2.7GB, Playwright browser binaries at 1.71GB left over from an old test job, TechSmith application data at 2.76GB, Notion's local cache at 1.73GB (a program long removed from the system), and a portion of the Android SDK installation at 3.7GB — except for the platform-tools folder which was retained because it contained adb.exe for Pixel phones.

There was another folder that appeared to contain 31.36GB of backup data from the phone thanks to Microsoft's Phone Link. It turned out to be a virtual file system supported by the feature, not actual local copies. Deleting it wouldn't free up any significant space, but it could disrupt the feature's integration. This is precisely the kind of small detail that an inexperienced person would misinterpret.

The results were even better than expected.

After the process was complete, the C: drive increased from 13.63GB of free space to 157.06GB of free space — 143GB was recovered on the 470GB hard drive, reducing its capacity from 97% full to 66.6% used.

Claude Code also flagged several items that it recommends leaving temporarily. These include the Adobe Cache (approximately 4.6GB), the Fluent Search index (3GB), the Slack cache (which should be cleared from within the application), and the Arduino15 SDK (10.2GB), which should be moved to a secondary drive instead of being completely deleted.

The real lesson isn't about disk space.

What does this say about AI agents and their ability to investigate complex systems?

Windows is designed to operate cautiously. The built-in cleanup tools only affect what Microsoft has clearly defined as safe to do so, without compromising program functionality or stability. Windows temporary files, the Recycle Bin, and leftover files from old updates are considered safe, but junk from other programs may not be acceptable. Anything that third-party applications leave behind in AppData, any model files from AI tools you've uninstalled, shader cache that your GPU has accumulated over months, even years—all of that is not displayed.

Claude Code can make that judgment because it doesn't work based on a fixed list. It scans what's actually there, explains the function of each folder, and explains the trade-offs of deleting anything before allowing you to make a final decision. And after recovering more than an entire inexpensive NVMe drive, your computer can finally run smoothly.