Originally Posted by swingdjted
I've heard (but am not sure the reason) that any Windows 7 boot and program drive should be at least 60 gigs for some reason. I've heard this from quite a lot of sources, but for some reason I have yet to hear the explanation for it.
That rule of thumb is for a default configuration. Some default stuff you may not need and for the others you can change the size allocation and/or the storage location.
A good chunk of space is set aside for the recycle bin and for the system restore features. Another chunk for a swap file. More space than you realize is needed for OS temporary files (many are deleted after the program that created them stops running, some just hang around for weeks). Windows 7 also needs space for the data created by all of it's default background tasks (monitoring this and that, maintaining history logs for all kinds of stuff, and data downloaded for the apps bundled with the OS). The default defragger needs unused space for it to work and the more space it has, the faster it can finish. SSDs do not need to be, and should not be, defragmented. They do need to be 'trimmed". Then of course, some space is needed for the apps (and their temps) you install.
The kicker is the Windows 7 folder itself. In 2.5 years mine has grown to 19.6 GB. 7.34 GB of that space is used by the "winsxs" sub-folder. That little gem is used to keep old system and dll files. Instead of over-writing old versions of these files, Windows 7 (and Vista) keeps them around so that apps that want to use the old versions are able to.
When you uninstall an app, the older dll versions installed by that app are supposed to be removed unless they are shared with something not removed. In practice, this rarely happens. Old system files updated by Windows updates and service patches are not removed unless you run special commands to delete them, after you are sure you don't need them (and when is that?). By the way, that 19.6 GB is after I ran these special delete commands and I have installed and uninstalled a lot of stuff over the past 2.5 years.
Then there's the rule about never using more than 75 to 85 percent of whatever space you have. This mainly relates to mechanical drives. Their reported transfer speed is an average across the whole platter. Transfers are much faster on the front part than the back. So to keep performance up, you don't want to store stuff on the back of the platter.
Finally, there's the dirty little secret about defects. Areas on the platters (and within SSDs too) simply do not work or stop working over time. The defect percentage can be, or become, larger than many vendors will admit (why has drive warranty times decreased?). The OS quietly skips these areas or moves data out of them when it detects a problem. Sometimes the data is not moved soon enough causing corrupt files. That's why the "chkdsk" utility or it's equivalent should be used on a regular basis.
There are other 'reasons', but those are the major ones.