对于你的错误Unable to open user login file ...,帮你找了一个:
VSS的文档里写得清清楚楚!!
Known Problems
Login to Local Visual SourceSafe Database Fails
Users that do not log in as an Administrator or Power User on the local computer cannot access a local SourceSafe database when it is installed on a Windows 2000 or WindowsXP NTFS partition. Attempts to access a SourceSafe database under these conditions raises the following error, "Unable to open user login file ...\VSS\data\loggedin\username.log" where username is your SourceSafe login name.
To work around this issue either install the SourceSafe database to a UNC path or log in as a Power User or Administrator.
For more details about this issue, see http://www.microsoft.com/windows2000/techinfo/planning/security/secdefs.asp.