You could delete these groups en masse using a report and a deployment package that runs against this report.
The command used in the deployment module should be the following:
net localgroup <GroupName> /delete
Modify the report below with the correct group names:
Select Top 1000000 tblAssets.AssetID,
tblAssets.AssetName,
tblAssets.Domain,
tsysAssetTypes.AssetTypename,
tsysAssetTypes.AssetTypeIcon10 As icon,
tblAssets.IPAddress,
tblGroupUni.Name As GroupName,
tblAssets.Lastseen,
tblAssets.Lasttried
From tblAssets
Inner Join tblAssetCustom On tblAssets.AssetID = tblAssetCustom.AssetID
Inner Join tsysAssetTypes On tsysAssetTypes.AssetType = tblAssets.Assettype
Inner Join tblGroups On tblAssets.AssetID = tblGroups.AssetID
Inner Join tblGroupUni On tblGroupUni.GroupID = tblGroups.GroupID
Where (tblGroupUni.Name = '
group1' Or tblGroupUni.Name = '
group2') And
tblAssetCustom.State = 1
Order By tblAssets.Domain,
tblAssets.AssetName