Safely deleting old W7 installation/folders on old drive?

I have an old W7 installation on my data storage HDD [E:\] that I would like to remove.
Which folders can I safely remove that do not contain any personal data?

On my current system I run W7 on an SSD and to save space I've outsourced all installation paths to the data HDD mentioned above.

If I delete the AppData folders on that old drive will that interfere with my current install or is it completely independant?

Can I completely delete the Windows folder and folders Windows creates automatically?
What's the cleanest approach to do so?

The folders in question would be:

E:\Windows
E:\ProgramData (hidden)
E:\Users\[User]\AppData

Is AppData or ProgramData on the old drive being used by my current active install or can I safely delete it?

Cheers!

Kaktussoft said:

"On my current system I run Windows 7 on an SSD and to save space I've outsourced all installation paths to the data HDD mentioned above."

What paths did you outsource and how?

Temp files incl. browser cache go to E:\Temp
When installing programs I select E:\Program Files(alt. E:\Program Files (x86)) as installation path.
Didn't change any other env. variables afaik when setting up the SSD.

The AppData/ProgramData on my active SSD/W7 installation are on the SSD itself, so I'm guessing the stuff on the E:\ is just the old stuff but I'm simply unsure whether I can safely delete those on E:\ without losing data that is actively being used by the system.

Kaktussoft said:

Just rename
E:\Windows
E:\ProgramData (hidden)
E:\Users

to

E:\Windows2
E:\ProgramData2 (hidden)
E:\Users2

And test. It isn't using e:\windows that's for sure. In command prompt

Code:

echo %programdata%

Is it pointing to C? If so fine...

Delete the folders on E a week later. First test if all is working fine. If you did what you told me it is safe to delete

Ha, good idea with the renaming, didn't think of it myself, doh!

%programdata% is indeed pointing to C.

Thanks a ton :)