Don't assume you can just generalize and delete things at will. There are database files that are needed (e.g. the Camera Raw database, if you have it set to save conversion parameters in a central location).
If you have specific files in a specific location find out what they do. List some folders here - someone will tell you what they're for.
Advice to uninstall and reinstall a perfectly good application is a bit extreme.
Have you tried the Windows disk space cleanup tool?
Yes, I used the disk cleanup tool, also I ran a defrag since i realized that i hadn't since installing cs5 and uninstalling cs4.
The majority of the used space is in User\Application Data\Adobe\Bridge CS4\Cache... then there are 4 subfolders \256, \1024, \data, \full. each of which have over a GB each, totaling about 8 GB. Which is 20% of my C:\ Drive
I'm not trying to generalize and assume that I can delete things at will, that is why I posed this question. I just wonder does CS5 access these old files from CS4, or are the new folders that CS5 created (that are identically named) all that is used?
And is the old CS4 folder (and its contents) obsolete and just taking up space?
Uninstalling does seem a bit extreme, but atleast since Im new to this still, I don't have an abundance of presets or anything like that that I'm too attatched to. I guess unless I get a better suggestion, I'm ok with starting with a clean slate if it gives me the space I need to keep going.
Thanks guys for the input so far.
If you've uninstalled CS4, I'd say anything with "CS4" in the path is fair game and can be deleted. Perhaps that's what Shunith meant. I'm sorry if I interpreted his comment wrongly.
It's important to note that there is really no "cross polination" between versions of Photoshop. As you probably know, you can have two different versions installed and they don't interfere with one another at all. So if you're not using CS4, those folders should be fair game.
Regarding the Bridge cache, I simply don't use Bridge myself, so I can't say for sure whether that can be deleted. I'm kind of glad I don't use Bridge if it uses up space like that.