Kinda random, but always shows up at boot, just after the welcome screen and as the desktop appears. I'm sure the system is clean (no virus)
I found this at MS which seems to maybe idscuss this issue
RSL link But when I try changing the RSL then my system wont boot due to "bad configuration"
By default, RSL is 25 percent of the size of paged pool. Setting up the size of paged pool (see PagedPoolSize value of the Registry key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\Session Manager\Memory Management) also affects the size of RSL.
You can also manually set the RSL:
1. Run the Registry Editor (REGEDT32.EXE).
2. Locate the key HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control.
3. Modify the value RegistrySizeLimit (create it first it if it does not already exist) to reflect the desired size, in terms of bytes.
NOTE: RegistrySizeLimit must have a type of REG_DWORD, and a data length of 4 bytes, or it is ignored. If you set the value RegistrySizeLimit to less than 4 megabytes (MB), it is forced up to 4 MB. If you set it to greater than about 80 percent of the size of paged pool, it is set down to 80 percent of the size of paged pool (it is assumed that paged pool is always more than 5 MB). If you set it to 0xffffffff the maximum size allowable (or 80 percent of paged pool, up to 102 MB) is set.
4. Shut down and restart Windows NT for changes in RSL to take effect.
Note A system restart is required after the RSL has been increased either through the graphical user interface (GUI) or the registry, because this change does not happen dynamically. If you do not restart the system, you may experience the following event:
Event Type: Error
Event Source: Userenv
Event Category: None
Event ID: 1000
Date: date
Time: time
User: NT AUTHORITY\SYSTEM Computer: name
Description: RegLoadKey failed. Return value Insufficient system resources exist to complete the requested service for C:\Documents and Settings\ntuser.dat.
In Windows NT 4.0, and Windows NT 4.0, Terminal Server Edition, the maximum paged pool size is 192 MB, so RSL can be a maximum of 153.6 MB. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: