You may need to stop IIS first for it to be successful... I just got this off the aspupload.com website:
To install AspUpload, download and run the setup application
aspupload.exe. The aspupload.exe setup will install both the AspUpload component (
aspupload.dll) and all the documentation into a directory on your hard drive that you specify during installation. Typically, it is
c:\Program Files\Persits Software\AspUpload, but it can be any other directory.
The install routine will automatically register the component DLL on your machine. During installation, your IIS-related services will be shut down and restarted.
If you need to move the AspUpload component to another server, it is sufficient to copy the file aspupload.dll (located under the \Bin subdirectory of the installation) to the other machine and register it there using the regsvr32 command-line utility. You may copy the file aspupload.dll to any folder on the second server's hard drive, e.g. c:\winnt\system32. To register the dll, run the MS DOS prompt and type the command
c:\>regsvr32 c:\winnt\system32\aspupload.dll
You should specify another path if necessary. If this server is already running an older version of AspUpload, you must remove it from memory prior to registering a newer version by shutting down all IIS services. To do that, type the following command at your DOS prompt:
c:\>net stop iisadmin /y
To bring the WWW service back up, type the command
c:\>net start w3svc
Other IIS services (such as FTP, SMTP, NNTP, Site Server, etc) can be restarted from the Services control panel.
The downloadable version of AspUpload will be fully functional for 30 days after installation and require a registration key afterwards. Once an AspUpload registration key is purchased, it should be installed in the system registry on the server (instructions will be sent to you via email along with the key).
Alternatively, a registration key can be specified in your ASP code via the Upload.RegKey property.
When switching from an eval to the full version, AspUpload does not have to be re-installed, or IIS restarted. To purchase an AspUpload registration key, visit http://www.aspupload.com/purchase.html - www.aspupload.com/purchase.html .