First - a workaround. Change your TEMP envirionment variable so you can function..
Right-click My Computer and click Properties, select Advanced, click Environment Variables button and edit the TEMP variable to C:\TEMP. Create C:\TEMP if it doesn't already exist. Log off and back on. You should now have an accessible Temp folder.
Next, after logging in as an administrator (local or domain), browse to the affected Temp folder in Windows Explorer. From Properties on that folder, select Security, click Advanced, select the Owner tab, select Administrators, check the "Replace owner on subcontainers" box, and click Apply. You can then select the Permissions tab and grant Administrators full-control, and Users-Modify access.
Log off and back on as yourself - you should be able to CD to the old temp folder and create/delete files. Restore your original TEMP variable definition if you can access the personal temp location.
NEVER play with CACLS using only the /G option, as that will remove all System access and permit only the account(s) you specify, requiring the steps above to be performed as an admin to recover access. IF you want to experiment with CACLS, use /E to edit the permissions and grant specific access to a different account. You can use runas to open a command window with alternate credentials and test access rights with little or no ill effects.
Glenn
