Flash 10 on Windows XP – Insufficient disk space!?
Its been a while since I booted into Windows XP on my desktop. Today I did. Since Adobe Flash Player 10 is out, I decided to upgrade the existing flash installation – In fact, my bank’s website won’t work without the upgrade. I downloaded the installer and started it, only to get an error:
You do not have sufficient disk space to complete this installation. Please free 5000 KB and try again.
My disk is nowhere close to being full. A little Googling pointed at a known bug in the installer – Apparently, the installer has C:\ hard coded in its installation path. So if your boot/system drive is not C:\, the installer dies with a very misleading message, quoted above.
I tried to follow the workaround suggested for Windows XP, but it did not quite work, since Changing the drive letter of the system volume or the boot volume is not a built-in feature of the Disk Management snap-in.
Further Googling pointed at a very simple solution. All you need to do is map C: to an existing folder (G:\ in my case). So I opened the Command Prompt, and executed the following command:
subst C: G:\
There. I started the installer again and had no problem this time!
Way to go Adobe..
PS: Don’t ask me how I ended up having G: as the system drive instead of the standard C:.

I have the same problem as mentioned however the subst command didn’t work for me. For some reason when i upgraded my computer it has assigned J:/ as my primary drive.
Im trying to install flash player but every time i try and install it pops up saying insufficient disk space? (Im guessing thats because its trying to find my C:/….which has nothing on it) How do i change this?
ive tried changing the drive letters but it wont let me do that either! HELP!!!
thanks
Jon
Jon, you say your primary drive is ‘J:/’, but you did use ‘subst C: J:\’ (back-slash, not a forward-slash), correct?
omg thank you SOOOO much. I’ve been pulling my hair out. When we reloaded the computer, had the printer hooked up and it grabbed C: first so the HD is F:. I thought I was going to go nuts!! This worked like a charm!!!! You are a GENIUS!!!
Same problem with Adobe Flash on XP Pro, but when I try substituting primary drive letter I get ‘Drive already SUBSTed’. I have a second internal HDD as well as an external HDD, which may have something to do with it I don’t know. I can alter all drive letters except the one assigned arbitrarily at installation. Any advice appreciated.
Update – it worked. I don’t know what threw me about the message ‘Drive already SUBSTed’ but threw me it did and I forgot to try the installer again. If I had a brain I’d be dangerous… Many thanks.
subst is not working for me
get the invalid parameter – c all the time i try
I’m having this same problem with trying to download flash player to firefox. What should be my C: drive is actually labeled as H: and although I tried your simple fix using the command prompt…it comes up with the following message to me: invalid parameter – C:
not sure what to do at this point. I also have internet explorer which has successfully downloaded flash player, however I do not like using that for internet access, and therefore need to get flash player to download for firefox still.
Help!!!!
Hung and Sarah,
I received the same error because one of my removable drives was already labeled C:, and it needed to be changed before the subst command would work.
You can find the instructions for changing a drive letter here: http://support.microsoft.com/kb/307844
I changed mine to H: temporarily and was able to use the original instructions to install Flash Player, no problems.
worked a treat thanks
I was caught by the same gotcha! Thanks for the easy solution.
I already have a C: drive, and wanted to install it on my D: drive. So I tried to subst the C to H and the D to C. THe first worked, but the second said invalid parameter C. Now, I have an exact copy of the C: drive, and I don't know how to get rid of it. Please Help.